Freshwater Fishes of Iran

Species Accounts

Gasterosteidae to Pleuronectidae

Revised:  16 July 2012

Gasterosteidae

Sticklebacks are found in marine and fresh waters of the cooler parts of the Northern Hemisphere. There are about 5 genera with about 18 species (Eschmeyer and Fong, 2011) of which one is native to Iran and another has been introduced.

This family of small fishes is characterised by a compressed, fusiform body; teeth in bands in each jaw but none on the tongue or palate; a protractile mouth; 3 branchiostegal rays; no postcleithrum; no scales but a series of plates along the flank variably developed, sometimes absent; 2 or more (usually 3-16) isolated spines in front of a soft dorsal fin (usually 6-14 rays); and a pelvic fin with a strong spine and only 0-2 soft rays.

The species in this family have been studied extensively (Coad, 1981f; Paepke, 1983; Wootton; 1976; 1984; Paepke in Bănărescu and Paepke, 2002). There is variation in colour, body form, spine numbers and development, and plate numbers. These variations in anatomy are matched by variations in biology such as habitat, feeding and reproduction. Variation in behaviour, biology and in speciation makes these small fishes, which have no commercial value, particularly important. Some of the variation is owing to environmental factors while some has a genetic basis. Several books have been devoted to them and thousands of scientific studies. Sticklebacks make excellent aquarium fishes. Their reproductive behaviour is complex, involving courtship and nest building. Some populations are anadromous and enter fresh water to breed.

Genus Gasterosteus
Linnaeus, 1758

This genus is characterised by having a modal count of 3 isolated strong spines in front of the soft dorsal fin, the body usually has strong bony scutes along the flank developed as a keel on each side of the caudal peduncle, a strong spine in the pelvic fin, and a complex reproductive behaviour.

The threespine stickleback, and related populations which act as good species but have not been formally named, have been studied extensively for their reproductive and other behaviours and for the insights that morphological variation and genetics throw on evolution.

Gasterosteus aculeatus
Linnaeus, 1758

Astara Shore, October 2009, courtesy of K. Abbasi

Common names

سه خار seh khar (= threespine), سه خاره (= seh khareh or sehkhareh), mahi seh khareh.

[trekhiglaya kolyushka or threespine stickleback in Russian; threespine stickleback].

Systematics

Gasterosteus aculeatus was originally described from Europe. The complex systematics of sticklebacks are not reviewed here. The Iranian specimens appear to be of a "marine" form with well-developed scutes on the flanks but their origin is not known.

Key characters

The 3 strong dorsal spines, strong pelvic fin spine with a single cusp at the base and the row of plates along the flank are distinctive.

Morphology

First dorsal fin comprised of usually 3 spines (2-4), second dorsal fin with 1 spine and 7-14 soft rays, anal fin with 1 spine and 6-13 soft rays, pectoral fin with 8-11, usually 10, branched rays and pelvic fin with 1 spine and 1 soft ray. Gill rakers 14-27, elongate and reaching as far as the fourth adjacent raker when appressed. Vertebrae 27-36. Plates along the flank 30-37; the Iranian specimens have a complete row of flank plates and a well-developed caudal peduncle keel, other populations may have an incomplete row or no plates at all. This species is very widespread and extremely variable over this range in the characters listed above and may well exceed the limits cited, e.g. dorsal fin spines are absent in some fish but the Iranian fish are of the typical marine form. The chromosome number is 2n=42 (Klinkhardt et al., 1995). The gut is short and s-shaped.

An Iranian specimen had 3 dorsal fin spines and 10 soft rays, 1 anal fin spine and 7 soft rays, 10 pectoral in rays and 1 spine and 1 soft ray in the pelvic fin. Scutes, including those forming the caudal peduncle keel, numbered 32. Total gill rakers numbered 19.

Sexual dimorphism

Breeding males develop a red belly and throat, blue sides, light blue back and have bright blue or turquoise eyes.

Colour

Marine populations are more silvery on the flanks than freshwater ones which are more olive. Generally the back is green-brown, olive or grey to blue-black, flanks olive to silvery and the belly silvery-white. Fins are generally clear. The peritoneum is silvery with large, widely spaced melanophores. Stream-dwellers have an irregular pattern of dark spots on the flanks and the back is an iridescent dark green.

Size

Reaches 11.0 cm.

Distribution

Found around the Northern Hemisphere in fresh and marine waters. Reported as an introduction to Iran by Abdoli (1993a, 1993c) and Coad and Abdoli (1993b), this species is found at the Neka Power Plant in Mazandaran near Behshahr, the Tajan River, the lower Gorgan River and Gorgan Bay, Bandar-e Torkeman, Gomishan Lagoon, the lower Babol, Heraz, Chalus, Tonekabon, Langarud, Polarud and Safid rivers, the Anzali Talab and the southeast Caspian Sea, the middle to upper Kashaf River in Khorasanin the Tedzhen (= Hari) River basin, and the upper Kal Shur and upper Jomein.rivers in the Dasht-e Kavir basin (Abbasi et al., 1999; Kiabi et al., 1999; Abdoli, 2000; K. Abbasi, pers. comm., 2001; Jolodar and Abdoli, 2004; Niksirat et al., 2006; Abdoli and Naderi, 2009). It is also caught by herring fishery ships on the coast of Iran (K. Abbasi, pers. comm., 2001).

Zoogeography

The exotic origin of the Iranian population is not known but the complete row of plates suggests a marine population. Sal'nikov (1995) reports this species from the southeastern Caspian Sea and moving into the Atrek River in Turkmenistan in large numbers. He refers to it as the Black Sea-Azov three-spined stickleback but it is unclear whether by this is meant its origin, its dispersal route or simply the nearest natural habitat for the species.

Habitat

These sticklebacks inhabit inshore coastal waters, lakes, ponds, rivers and streams, and may be anadromous. Marine and lake fish can be pelagic. They are often found among algae. In Iran, this species is caught at 30-100 m by herring fishery ships (K. Abbasi, pers. comm., 2001).

Age and growth

Maximum life span is a little over 3 years although some fish probably live only 1 year and a few months, dying after they spawn. Paepke in Bănărescu and Paepke (2002) is a recent review of literature.

Esmaeili and Ebrahimi (2006) give a significant length-weight relationship based on 500 Iranian fish measuring 3.60-7.20 cm standard length. The a-value was 0.0090 and the b-value 3.428 (a b-value < 3 indicating a fish that becomes less rotund as length increases and a b-value >3 indicating a fish that becomes more rotund as length increases). Patimar et al. (2010) studied this exotic in the Gomishan Wetland of the southeast Caspian Sea. Maximum ages were 2+ years for males and 3+ years for females, and the length-weight relationship was W = 0.0042TL^3.711 for immature fish, 0.0095TL^3.1328 for males and 0.0075TL^3.4678 for females. The sex ratio was 1:2.63 in favour of females.

Food

Food is various crustaceans, aquatic and terrestrial insects, snails, worms, fish eggs and fry including their own species, and a wide variety of other available organisms taken both on the bottom or pelagically. Copepods and chironomids tend to dominate as food items. Again Paepke in Bănărescu and Paepke (2002) is a recent review of literature.

Niksirat et al. (2010) found stomach contents in the southeast Caspian Sea comprised gammarids, Nereis sp., chironomids, fishes, oligochaetes, fish eggs and hirudineans. Gammarids dominated in December and January and were replaced by Nereis in February. The preference shifted to chironomids in July and to fishes in October.

Reproduction

Spawning occurs from April to October, varying with locality over the wide range of this species. The male parental cycle at one site in Canada lasts 9-15 days with female interspawning intervals of 19 days. Males and females only complete one spawning here, though laboratory studies show males capable of 5 reproductive cycles and females of producing a clutch of eggs every 3-4 days. Harsh physical conditions are probably the cause. The male builds a barrel-shaped nest in shallow, sandy areas from plant fragments glued together on the bottom with kidney secretions. The nest is in an open area but near vegetation. The nest has an opening at each end. The male has a complex courtship dance with zig-zag motions and a leading motion to the nest. A responsive female adopts a submissive head up position, which also reveals the egg-swollen belly. The male pokes his snout at the nest to indicate its position to the female, tipping his head sideways to display the bright red throat. The male jabs the female with his snout through the nest wall after she enters to stimulate egg release. He then follows the female through the nest to fertilize the eggs and drives the female away. Several females may spawn in one nest which can contain up to 1026, yellowish 1.8 mm diameter eggs. The male guards and fans the eggs and guards the fry.

Patimar et al. (2010) in their Gomishan Wetland study found reproduction to occur in March-June, peaking in April. Large yolk-filled eggs with a mean diameter of 1.317 mm (maximum 1.96 mm) numbered 128-885. Small white opaque eggs were also found in the ovaries with a mean diameter of 0.549 mm and numbered 311-4709. The mean absolute fecundity was 1241.69 eggs and mean relative fecundity was 535.24 eggs/g body weight. Niksirat et al. (2010) found the breeding season in the southeast Caspian Sea began in March and lasted 5 months. Condition factor somatic condition factor and hepatosomatic index increased at the beginning of the spawning season and decreased as it progressed.

Parasites and predators

Many fishes and birds, and even snakes, seals and small mammals, feed on sticklebacks despite their protective spines which are locked erect when they are disturbed. Niksirat et al. (2006) record Corynosoma strumosum in this species from the Gomishan Lagoon and Hosseinifard et al. (2010) the acanthocephalan Bolbosoma caenoforme from fish in the Shazdeh River, Babolsar.

Economic importance

The threespine stickleback has received much attention for its evolutionary interest, behaviour and utility as an experimental fish. They may be predators on fish eggs and larvae, and competitors for food, of more commercially important species. The Baltic Sea area has had sufficient numbers to support an oil extraction industry (Paepke in Bănărescu and Paepke, 2002). In the Iranian parts of the Caspian Sea this exotic may compete with juvenile sturgeons for food and its spread may account for the disappearance of the native Pungitius platygaster (Niksirat et al., 2010).

Conservation

Lelek (1987) classifies this species as intermediate to rare, locally vulnerable in Europe. As a recently recorded exotic species in Iran it is still comparatively rare but should not be accorded any status.

Further work

The spread of this exotic species should be monitored and its effects on native fishes observed.

Sources

Iranian material: CMNFI 1993-0144, 1, 57.3 mm standard length, Mazandaran, Neka Power Plant (36º51'48"N, 53º23'24"E).

Genus Pungitius
Coste, 1848

This genus of sticklebacks is found in North America and Eurasia with about 3-5 species (opinions vary) but only 1 in Iran (Paepke in Bănărescu and Paepke, 2002).

It is distinguished by a series of 7-12 small spines (much smaller than in the genus Gasterosteus) in front of the dorsal fin, arranged alternately to the left and right, the pelvic fin has 1 spine and 0-1 soft rays, and the skin is naked or has small bony plates in a row along mid-flank.

Pungitius platygaster
(Kessler, 1859)

Common names

nohkhar or nokhareh (= ninespine), mahi seh khareh nama (= threespine-like fish), mahi khardar (= spiny fish).

[tikan balig in Azerbaijan; malaya yuzhnaya kolyushka or southern ninespine stickleback in Russian; Ukrainian stickleback].

Systematics

Gasterosteus platygaster was originally described from Odessa and Aleshki on the Dnieper in the Ukraine.

Gasterosteus pungitius var. Kessleri Yakovlev, 1870 and Gasterosteus pungitius var. niger Yakovlev, 1870 both from lakes near Astrakhan, Volga River delta, Russia, Gasterosteus platygaster var. caucasicus Kessler, 1877 from Transcaucasia, and Pygosteus platygaster nuda Berg, 1905 from Lake Charkhal in the Ural River valley, are synonyms. Syntypes of the latter are in the Zoological Institute, St. Petersburg (ZISP 10613) (Eschmeyer et al., 1996; Kottelat, 1997).

Münzing (1969) retains this taxon as a distinct species but suggests that it may only be a subspecies of Pungitius pungitius (Linnaeus, 1758). Ziuganov and Gomeluk (1985) studied hybridisation of this species and P. pungitius under experimental conditions and consider that they are at most subspecifically distinct. They found 9 out of 19 morphological characters distinguish this species from P. pungitius as well as a differing ecology. However there were no ethological, nor presumably genetical, isolating mechanisms since F₃ hybrids were fertile. Ziuganov (1991), Keivany (1996), Keivany and Nelson (1997) and Keivany et al. (1997) recognise P. platygaster as a distinct species since it is 100% distinguishable from other species in the genus. However, Keivany and Nelson (2004) found that P. platygaster lay within a polychotomy with subspecies of P. pungitius. P. platygaster is retained as a full species until the two taxa come into contact naturally, which will test the hypothesis of Ziuganov and Gomeluk (1985).

Key characters

The small spines usually alternating left and right in front of the dorsal fin are distinctive.

Morphology

Characterised by 22-34 bony plates along the flank, perhaps a response to predators (Ziuganov and Gomeluk, 1985). The first 4-12 plates are large (Keivany and Nelson, 1998). There is no caudal peduncle keel. The plates in young fish are minute fragments of bone and difficult to see, especially posteriorly. The body form is less elongate than the related Pungitius pungitius. Dorsal fin spines slightly curved, 7-11 (in Iranian specimens 8(7), 9(11)) and branched rays 6-11, anal branched rays 6-10, pectoral fin rays 9-11 (usually 10), and pelvic fin with 1 serrate spine and 0-2 soft rays, usually 1. Rarely up to 4 dorsal fin spines may follow the midline and not alternate markedly in Iranian fish. The last spine in the series is usually slightly longer than the others. Vertebrae number 29-31 (in Iranian specimens 29(9), 30(9)) and gill rakers 7-13, reaching the base of the second raker below when appressed. The gut is short and s-shaped. The chromosome number is 2n=42 (Klinkhardt et al., 1995).

Sexual dimorphism

Colour at breeding is the most evident sexual dimorphism.

Colour

Females are olive with greenish-brown stripes, patches and mottling even during spawning. Males are jet black and develop a blue-white colour on the posterior side of the ventral spines as a stimulus for leading the females. The specimens described as var. kessleri were light grey and var. niger were black, perhaps non-spawners and spawners. The peritoneum is silvery.

Size

Attains 7.0 cm standard length.

Distribution

Found in the Black, Caspian and Aral seas and their basins. Reported from the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea, the Anzali Mordab, Ameerkalaye Lagoon near Lahijan, and lower reaches of rivers such as the Safid, Shakhzaderud (lower Babol), lower Karasu and Gorgan (Derzhavin, 1934; Holčik and Oláh, 1992; Nejatsanatee, 1994; Abbasi et al., 1999; Kiabi et al., 1999; Abdoli and Naderi, 2009). Keivany (1996) considers it to be rare on the southern Caspian Sea coast. Jolodar and Abdoli (2004) report it from brackish portions of the Caspian Sea and rivers falling into it, being more numerous in the Gomishan Lagoon.

Zoogeography

Pungitius platygaster aralensis (Kessler, 1877) is reported from the western Uzboi lakes in Turkmenistan (Shakirova and Sukhanova, 1994) and with canal construction projects may ultimately reach the Caspian Sea basin.

Habitat

Described as a benthivore living a cryptic life in weed beds (Ziuganov and Gomeluk, 1985). It can be found in fresh and brackish waters.

Age and growth

In the Volga delta, mature adults are 3.2-5.8 cm long (mean 4.0 cm) from April to July and young-of-the-year are 1.2-2.8 cm long (mean 2.3 cm). Life span appears not to exceed 2 years as only sexually mature adults are caught in spring (Fortunatova, 1961) although a few fish may reach 3 years and maturity may be attained shortly before reaching 1 year (Paepke in Bănărescu and Paepke, 2002).

Food

Diet is small invertebrates including chironomids. Eggs of commercially important fishes may be eaten.

Reproduction

Reproduction can occur at high temperatures, e.g. 28°C, at which eggs of P. pungitius die. Spawning begins at 17°C. In the Volga delta spawning begins in late April and continues to the middle of June but is most intensive in the middle of May. Dense schools are formed which disperse after spawning with the fish becoming secluded in the heavy vegetation which develops at this time (Fortunatova, 1961). Fecundity is up to 90 eggs. Males build nests out of the remains of the previous year's vegetation glued together with kidney secretions (Fortunatova, 1961). A female indicates readiness to spawn by a head-up posture near the nest. The male performs a zig-zag dance and leads the female to the nest entrance by angling his head down at 60°, flashing his blue-white pelvic spines and moving by short jerks. The female enters the nest, the male taps her caudal peduncle to stimulate egg deposition, she leaves and the male enters the nest to fertilize the eggs. The leading part takes only 10 seconds.

Parasites and predators

The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984) as are such fishes as Perca fluviatilis, Esox lucius, Silurus glanis, Aspius aspius and Sander lucioperca (Fortunatova, 1961) and Neogobius melanostomus, water snakes, pond turtles, frogs and fish-eating birds (Ziuganov, 1991).

Economic importance

None; although Paepke in Bănărescu and Paepke (2002) consider it important as a predator on mosquito larvae (and hence a biological control for malaria) in smaller water bodies.

Conservation

Holčík and Oláh (1992) report the loss of this species from the Anzali Mordab, where it was once abundant, through a change in the environment to fresh water from brackish, siltation, oxygen depletion and loss of spawning grounds. Keivany (1966) considers it to be rare on the southern Caspian Sea coast while Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include medium numbers, widespread range (75% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin.

Further work

The distribution and biology of this species in Iranian waters needs further investigation.

Sources

Descriptions of breeding and some meristic characters are taken from Münzing (1969) and Ziuganov and Gomeluk (1985).

Iranian material: CMNFI 1970-0552, 1, 16.0 mm standard length, Gilan, Sowsar Roga (37º27'N, 49º30'E); CMNFI 1970-0554, 12, 17.5-22.0 mm standard length, Gilan, Pir Bazar Roga (37º21'N, 49º33'E); CMNFI 1970-0567, 2, 17.7-21.4 mm standard length, Gilan, Pir Bazar Roga (37º21'N, 49º33'E); CMNFI 1970-0591, 2, 15.8-17.4 mm standard length, Gilan, Pir Bazar Roga (37º21'N, 49º33'E); CMNFI 1979-1215, 1, 22.3 mm standard length, Gilan, Sowsar Roga (37º27'N, 49º30'E).

Syngnathidae

Dalaki River, Helleh, 25 December 2011, courtesy of H. R. Esmaeili

Common names

مارماهي (= mar mahi, meaning snake fish), marmahi-ye khardar (= snake fish with spines or spiny snakefish), مارماهي شاخدار (= mar mahi shakhdar).

[salbouh abu-el-sian, salbu-al-sayan, saebouh abou siyan; abu salmabah; simack, englisi or englese at Aleppo, marmaritch or marmarij at Mosul, all in Arabic; Mesopotamian spiny eel, Euphrates spiny eel].

Systematics

Ophidium Mastacembelus was originally described from "Aleppo" and from the "River Kowick" (= Quwayq) in the book by Russell (1794).

Ophidium Simack Walbaum, 1792 (non-binomial), Rhynchobdella haleppensis Bloch and Schneider, 1801 and Mastacembelus syriacus Gronow in Gray, 1854 are synonyms. Mastacembelus aleppensis Günther, 1861 is an unjustified emendation of haleppensis (Eschmeyer et al., 1996). Wheeler (1956) and Sufi (1957) discuss the names of this species more fully.

Three syntypes of Ophidium Mastacembelus from "Aleppo" are in the Natural History Museum, London under BM(NH) 1955.6.25:4-6, measuring 289.5-544.0 mm standard length.

Çakmak and Alp (2010) found morphological differences between river and reservoir populations in Turkey, but none for meristic traits. Some differences appear to be associated with habitat type, a thicker and longer caudal peduncle in river populations may enhance swimming ability in faster water and longer lower jaws in river fish could be a feeding adaptation, for example.

Key characters

The eel-like body with 30-35 short, sharp dorsal spines, long soft dorsal and anal fins and the unique flexible snout flanked by tubular nostrils distinguish this species from all other Iranian fishes.

Morphology

The mouth gape extends back as far as the anterior eye margin or somewhat forward of this point. The posterior nostril is slit-like. The structure of the elongated eye, typical of streamlined forms, has been described by Jasim (1998) based on Iraqi specimens. The regular, mosaic pattern of the retina is associated with fishes that search for their food and the double cone structure may be associated with detection of moving prey.

Soft dorsal rays 68-90, soft anal rays 70-90 after 3 spines, pectoral rays 18-24 and total vertebrae 85-88. The penultimate spine in the dorsal fin is the longest and the central anal spine is the longest. Iranian specimens had 31(2), 32(6) or 33(4) dorsal fin spines, 19(5) or 20(3) pectoral fin branched rays, and total vertebrae 86(1), 87(1). The diploid chromosome number is 2n=48, arms number NF=88 and there are 11 metacentric, 9 submetacentric and 4 subtelocentric chromosome pairs (Esmaeili et al., 2006).

Scales minute but covering the whole body, under the eye, below the posterior nostril and between this nostril and the maxilla. Each scale has a central to anterior focus with radii on all fields and an oval shape. There is a strong preorbital spine under the eye, present in some fish but concealed under the skin or absent in others. Teeth form broad bands in both jaws with the outermost teeth the largest. There are no gill rakers but spinulose patches lying flat on the arch. The gut is an elongate s-shape.

Sexual dimorphism

Unknown.

Colour

The body is blotched and barred, often forming a reticulate pattern, or a series of mid-flank blotches most evident posteriorly and sometimes running together as a stripe anteriorly. Flank blotches may form up to 17 bars running from the dorsal to the anal fin across the flank. The back is blackish to brown, olive, greyish or blue-grey, the lower flank is spotted yellow or is yellow overall and the belly is white to yellowish. A series of about 20-24 black to blackish-brown, oval spots ringed with a lighter brown follow a dark, broad but irregular stripe on the head and anterior back in the mid-line. Dorsal, anal and caudal fins are yellowish with the dorsal and caudal fins finely barred and the anal fin continuing the pattern on the adjacent body. The anal fin may be almost immaculate. The soft dorsal fin may have vermiculations rather than bars. The pectoral fins are yellowish and are finely barred. The peritoneum is brownish, with numerous fine melanophores. Small fish (about 7.7 cm total length) can be an almost uniform grey-brown to brown-green, with yellowish brown on the fins and the tail region, and fin spots are dark to absent. There is a thin bar extending vertically down or obliquely back from the eye.

Size

Reaches 76.9 cm total length (Gümüş et al., 2010), probably larger to almost 1 m.

Distribution

Found in the Quwayq, Orontes and Tigris-Euphrates basins. In Iran its is recorded from the Tigris River, Gulf and Kor River basins, including lakes Zaribar and Marivan, and the Fasa, Dez and Dalaki rivers (Löffler, 1957; Abzeeyan, 5(5):III, 1994; Gh. Izadpanahi, pers. comm., 1995).

The record of Mastacembelus armatus (Lacepède, 1800) reported by Mokhayer (1981b) from the Kor River basin is probably a mis-identified Mastacembelus mastacembelus.

Abdoli (2000) maps this species from the Kor and Pulvar rivers of the Kor River basin; the middle and lower Shur River tributary of the Dasht-e Palang, the upper Mand and Qara Agaj, the middle and upper Hilleh and the upper Zohreh rivers of the Gulf basin; the Jarrahi, lower Karun, middle and lower Dez, Karkheh, Simarreh and lower Kashkan rivers of the Tigris River basin.

Zoogeography

Wikimedia Commons

Common names

mahi-ye khardar, bacheh suf (= baby suf), mahi suf rudkhanehi Astrakhan (= Astrakhan river suf fish, presumably an old name at this Russian locality), سوف حاجي طرخان (= suf-e Haji Tarkhan meaning Astrakhan suf, an old name no longer in use), suf-e rudkhaneh'i (= river suf), hashtarkhan suf.

[xanibaligi in Azerbaijan; okun' in Russian; perch, European perch, Eurasian perch, river perch].

Systematics

Perca fluviatilis was originally described from Europe.

Collette and Bănărescu (1977) refute earlier workers who maintain that this species and the North American yellow perch (Perca flavescens (Mitchill, 1814)) were the same or at best subspecies, e.g. see Svetovidov and Dorofeeva (1963) and Čihar (1975) for opposing views. Collette and Bănărescu (1977) base their conclusion on the observation that the predorsal bone is anterior to the first neural spine in fluviatilis rather than extending between the first and second neural spines as in flavescens. Other characters also exist to separate the two species. Data on the North American perch cannot therefore be used uncritically as a summary of biology for the Iranian perch.

Key characters

Characters of the genus serve to identify the single, distinctive species.

Morphology

Lateral line scales 40-78; scale rows above lateral line 7-10; rows below lateral line 12-22; and predorsal scales 10-21. Scales have very fine circuli, few anterior radii, a posterior focus and a markedly incised anterior margin where about 5-7 radii terminate. The exposed part of the scale is coarse and is the base for ctenii, best developed on the margin. Dorsal fin spines 12-18; dorsal soft rays 8-17, usually 12-15, after 0-5, usually 2-3 spines; anal fin soft rays 6-11 after 1-3 spines; pectoral rays 9-17; and pelvic rays 4-6, usually 5 after 1 spine. Gill rakers 23-25, reaching between the third and fourth rakers below when appressed usually but variable in length with diet, shortest when feeding on fish, longer when food is zooplankton. The gut is s-shaped with a large anterior loop and there are 3 pyloric caeca. Vertebrae 38-44, and gill rakers 14-29. The chromosome number is 2n=48 (Klinkhardt et al., 1995).

Meristic values for Iranian specimens are:- lateral line scales 59(3), 60(2), 61(2); scale rows above lateral line 9(7); rows below lateral line 17(4), 18(2), 19(1); scales between lateral line and pelvic fin 6(2), 7(5); predorsal scales 10(1), 11(2), 12(1), 13(2), 14(1); and caudal peduncle scales 24(1), 25(1), 26(1), 27(3), 28(1); dorsal fin spines 14(2), 15(1), 16(4); dorsal soft rays 13(2), 14(5) after 2 spines; anal fin soft rays 8(3), 9(3), 10(1) after 2 spines; pectoral rays 11(2), 12(2), 13(3); pelvic rays 5(7) after 1 spine; vertebrae 40(2), 41(3), 42(1).

Sexual dimorphism

Males have longer paired fins than females and are brighter in colour. Females are larger than males of the same age.

Colour

Colour can be affected by diet, especially in the fins which are reddest when feeding on certain crustaceans, and by habitat depth but generally the colour is stable. Fish from along the shore in weedy habitats are greenest, those in open water a pale yellow, and at depth are darker. The body is an overall greenish-yellow with 5-9 black bars on the flanks. The first dorsal fin is grey with black markings on the membranes. The first spine is often black and deep black membranes are evident between spines 1 and 2 and the last 4 to 5 spines. The second dorsal fin is greenish-yellow with melanophores on the rays and membranes, the pectoral fin yellowish and other fins pinkish to yellow to silvery-white. Paired and caudal fins have much sparser melanophores than the second dorsal fin. The lower part of the caudal fin is orange to red. Peritoneum silvery and speckled with melanophores.

Size

Reaches 68.0 cm and possibly 10.4 kg but most are much smaller than this.

Distribution

Found from the British Isles across northern Eurasia to eastern Siberia. Their presence in the Caspian Sea basin of Iran is their most southerly natural distribution. Also introduced to South Africa, Australia and New Zealand.

In Iran it has been reported from the Anzali Mordab (= Talab) and its outlets, Ab Kenar and Siah Keshim Protected Region in the Anzali Talab, at Bandar Anzali, Bandar Anzali beach, the lower Safid River and the Caspian Sea near Bandar Anzali (Derzhavin, 1934; Holčík and Oláh, 1992; Riazi, 1996; Abbasi et al., 1999; Abdoli, 2000; Abdoli and Naderi, 2009). Jolodar and Abdoli (2004) restrict its presence to the Anzali lagoon and rivers draining into it. Anderson (1880) reports perch to be abundant in the Lar River near Tehran, but this is probably a misunderstanding at this early date.

Zoogeography

Its closest relative is found in North America and they were once thought to be the same species on both continents.

Habitat

Distribution is limited by an inability to survive a temperature of 31°C for more than a few hours, by an inability to tolerate salinities above about 10-12‰ and by avoidance of waters with an oxygen level of less than 3 ml/l. The upper lethal temperature is 33.5°C (Collette et al., 1977). It is not found in the Caspian Sea proper because of the latter limitation. Fresh water is required for spawning. Riazi (1996) reports that this species is native (resident) to the Siah-Keshim Protected Region of the Anzali Mordab and it is also reported from swamps near Hendeh Khaleh in Gilan at about 37°23'N, 49°28'E.

Optimal conditions are large, weed-free, moderately deep, mesotrophic waters with food fish such as Rutilus rutilus readily available. Turbidity is a limiting factor for this species which depends on sight to feed. It is found only in the lower reaches of rivers along the Iranian shore and does not penetrate upstream (Berg, 1948-1949). Nevertheless it can be found in both running and still water and in both small and large water bodies.

Perch are a schooling fish, arranged by size and age. Schools form in the morning and disperse as dusk falls. Schools usually number about 50-200 fish but schools in the thousands are reported. There is a nocturnal resting area and perch move from it to a diurnal active area. The perch may move short distances within a lake and in large water bodies over 90 km but show strong homing tendencies. Seasonal movements are between feeding, spawning and overwintering areas.

Different morphs are found in some areas, depending on habitats: one small, slow- growing, dark and gregarious, feeding on small crustaceans, and found in reed beds, the other large, fast-growing, light and solitary, feeding on fish, and found in open waters.

Populations in the Safid River were supposedly increased after construction of the dam which reduced water flow and raised temperatures.

Age and growth

Maturity in males is usually attained in the second year of life (at only 5-12 cm long) with females maturing 1-2 years later (at 12-18 cm or larger). However some males may mature during their first year or as late as their third. Females grow slightly faster than males after the first 1-2 years. Eutrophication may reduce the age of first maturity because of increased growth rates. Perch in different habitats within the same water body, e.g. weeds beds as opposed to open water, will show different growth rates and body forms. Growth over the whole range of the species varies markedly. Generally fish at age 2 which are greater than 20 cm total length are characterised as having very good growth, moderate growth would be fish at age 3 greater than 16 cm total length while a very poor growth would be evidenced by all fish in the population being less than 16 cm total length. Life span is up to at least 21 years and under artificial conditions up to 27 years, perhaps even 50 years. A maximum age of 11 years is given for a Volga delta population examined by Makarova (1986).

Nezami et al. (2004) found fish in the Amirkelayeh Lagoon on the Caspian coast of Iran were in age groups 1+ to 6+, a total length of 9.5-33.5 cm and a weight of 10.5-350.0 g. Heydarnejad (2009) gave the length-weight relationship for an Iranian sample as W = 0.0145TL^3.011.

Food

Food for small perch is zooplankton such as rotifers, switching to insect larvae, crustaceans, molluscs and leeches with growth (larger than about 20 mm). Growth is enhanced if fish and crayfish are available. Fish predominate in the diet at a range of sizes between 10 and 25 cm. In the Caspian basin, Rutilus rutilus, Blicca bjoerkna, Pungitius platygaster and gobies (Gobiidae) are eaten (Makarova, 1986). Some slow-growing perch may feed on plankton until 2-3 years old. Cannibalism is common. Maximum feeding levels occur in summer and by autumn has fallen to a maintenance level (Collette et al., 1977; Popova and Sytina, 1977). Feeding is a daylight and highly visual activity. Feeding is more effective in shoals as the perch attempts to seize other fish by the head and, if an individual perch misses, then other members of the shoal have an opportunity to seize the prey. Large perch lie in wait for passing prey items and then dart out to seize them. Unlike northern pike, perch will pursue a prey item if it tries to escape.

In the Amirkelayeh Lagoon diet varied according to age, season and sex, and comprised a wide variety of organisms such as water bugs, odonates, gammarids, plant materials, chironomids, Tinca tinca, hemipterans, Perca fluviatilis, snails, Syngnathus caspius, Gambusia holbrooki, Pungitius platygaster, dipterans, branchiopods, trichopterans, tubifex, frogs and shrimps. The species is an omnivore here and a cannibal.

Reproduction

Spawning occurs in the spring in shallow water, 0.5-3.0 m deep, end of March to early June in the Volga Delta (Makarova, 1986). In Dagestan spawning is from the end of March to the beginning of April and lasts 10-15 days (Shikhshabekov, 1978), elsewhere only 2-3 days. Water temperatures are around 11°C on the Volga (Lönnberg, 1900b) and above 8°C in Dagestan (Shikhshabekov, 1978) but can occur under ice at 4°C. Up to 80% of the spawning population in the Volga Delta is female (Makarova, 1986). There is a spawning migration from deepwater resting areas to shallow spawning areas. Males precede females onto the spawning ground by days or weeks and remain behind after spawning. Brackish-water populations migrate into fresh water. Spawning itself can occur by day or by night.

Although temperature is the major factor affecting the timing of spawning, the occurrence of spring floods is significant in some populations as it gives access to inundation zones of large rivers.

Eggs are twisted around plants, roots and logs in an egg-strand, a cylindrical, hollow, twisted structure up to 3.75 m long, 3.8 cm thick and 8 cm wide. This structure offers protection from predators, fungal infections, desiccation, mechanical damage and smothering in the mud. Egg diameters reach 2.5 mm and fecundity 300,000 eggs. Fecundity increases with age and depends on food supply as in most fish species. As many as 15-25 males queue up to fertilize the egg-strand, following the female as she twists around the logs and plants, rubbing against the plants to void the eggs. The female drives the males away from the egg-strand after fertilisation and may guard the egg-strand for some hours.

Parasites and predators

Sander lucioperca, Esox lucius and Lota lota are predators on perch in the Caspian basin and doubtless other large fishes and birds take this species. Cannibalism begins as early as the fry stage when fish only 2.1 cm long eat smaller fry.

Mokhayer (1976b) records the protozoan Trypanosoma percae from this species in the Caspian Sea basin, the nematode larva Eustrongylides excisus and the annelid Piscicola geometra. Khara et al. (2006a) record the eye fluke Diplostomum spathaceum for this fish in the Amirkalayeh Wetland in Gilan. Sattari et al. (2002) and Sattari (2004) records the presence of the nematode, Eustrongylides excisus. This parasite can damage muscles in commercial species and render them unsuitable for sale. Sattari et al. (2004; 2005) surveyed this species in the Anzali and Amirkelayeh wetlands, recording Raphidascaris acus, Eustrongyloides excisus and Camallanus lacustris. Khara et al. (2005) examined this species in the Amirkalayeh Wetland and found its diversity of parasites to be less than other predatory species such as Esox lucius. Parasites recorded were Camallanus lacustris, Diplostomum spathaceum, Lemaea sp., Argulus sp., and Dactylogyrus sp. Sattari et al. (2007) record the nematode Eustrongylides excisus and the digenean Diplostomum spathaceum in this species in the Anzali wetland of the Caspian shore. Barzegar et al. (2008) record the digenean eye parasite Diplostomum spathaceum from this fish. Barzegar and Jalali (2009) reviewed crustacean parasites in Iran and found Achtheres percarum on this species.

Economic importance

Holčík and Oláh (1992) report a catch of only 15 kg in the Anzali Mordab in 1990. This species has been studied for aquaculture in Iran.

Robins et al. (1991) list this species as important to North Americans. Importance is based on its use in aquaria and aquaculture, as food, in sport, in textbooks, in experiments and because it has been widely introduced outside its natural range. It has been implicated in ichthyootoxism (Coad, 1979b), the symptoms of egg poisoning being summarised under the genus Schizothorax.

Conservation

Illegal fishing and non-standard nets threaten stocks of this species (Annual Report, 1995-1996, Iranian Fisheries Research and Training Organization, Tehran, p. 55, 1997). Kiabi et al. (1999) consider this species to be vulnerable in the south Caspian Sea basin according to IUCN criteria. Criteria include commercial fishing, sport fishing, medium numbers, habitat destruction, limited range (less than 25% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin.

Further work

The status of populations of this species in Iran should be carefully monitored in view of the threats outlined above.

Sources

General biology is based on Thorpe (1977) and Craig (1987), and there is extensive European angling literature on this species.

Iranian material: CMNFI 1970-0510, 1, 156.8 mm standard length, Gilan, Golshan River (37º26'N, 49º40'E); CMNFI 1979-0685, 1, 71.5 mm standard length, Gilan, Safid River around Mohsenabad below Dehcha (no other locality data); CMNFI 1980-0123, 1, 68.9 mm standard length, Gilan, Safid River around Dehcha above Mohsenabad (no other locality data); CMNFI 1980-0127, 1, 152.8 mm standard length, Gilan, Caspian Sea near Hasan Kiadeh (37º24'N, 49º58'E); CMNFI 1980-0148, 2, 118.2-142.1 mm standard length, Gilan, Pir Bazar Roga (37º21'N, 49º33'E).

Genus Sander
Oken, 1817

This genus is found in both North America and Eurasia and contains 5 species. There are 3 species in the Caspian Sea basin, 2 of which are reported from Iran. The Shahid Beheshti hatchery on the Safid River breeds the third species, S. volgense (Gmelin, 1789), a northern Caspian Sea species, according to Raymakers (2002) but it is unclear if these have been released and have established populations in the southern Caspian Sea.

The genera Stizostedion Rafinesque, 1820 and Lucioperca Schinz in Cuvier, 1822 are junior synonyms of Sander (see Kottelat, 1997). The pike-perches are elongate and compressed, have large jaws reaching back beyond mid-eye level, canine teeth on the jaws and palatines, the preopercle is serrated posteriorly and has spines ventrally, the opercle has a weak, flat spine at its postero-dorsal corner, cheeks are naked or scaled only dorsally, there are 7-8 branchiostegal rays, adult gill rakers are densely denticulated tubercles, in young denticulated rods, and the lateral line continues onto the caudal fin with accessory lateral lines on the upper and lower caudal lobes. Divergence between North American and Eurasian members of this genus may have occurred in the middle to late Miocene or in the Pliocene (Billington et al., 1990; 1991; Faber and Stepien, 1998).

Sander lucioperca
(Linnaeus, 1758)

Wikimedia Commons

Common names

سوف (= suf), سوف معمولي (= suf-e ma'muli or soof-e-maamooli, meaning common suf), sibey(ak) in Gilaki, ? sevideh.

[sif, caysifi or quaysifi in Azerbaijanian; adaty silebalyk in Turkmenian; sudak in Russian; pike-perch, European pikeperch, zander].

Systematics

Perca Lucioperca was originally described from European lakes. This may be the fish referred to as sevideh from the Langarud Mordab by Holmes (1845). However the word may be sepideh which means "the white one" and may in fact refer to Rutilus frisii, the safid mahi. Akbarzadeh et al. (2007, 2009) identified three distinct populations in the southern Caspian Sea using a truss analysis with morphometric characters (body heights and caudal peduncle measures) showing better discrimination than meristic characters. Gharibkhani et al. (2009) examined the population genetic structure of fish from the Talesh coast, Anzali Wetland and Chaboksar coast and found them to be genetically differentiated, with consequences for conservation.

Key characters

This species is separated from S. marinum by the dorsal fins being close together, obviously much less than the eye diameter apart, the anal fin spines are not closely joined to the soft rays, the interorbital width is less than, or equal to, the vertical eye diameter in adults, the upper jaw extends rearwards on a level behind the posterior eye margin in adults (under the rear of the eye in young), there are usually more than 18 soft rays in the dorsal fin, and the spiny dorsal fin bears large spots.

Morphology

Lateral line scales 75-150 (this wide range from various literature sources presumably includes counts of scales in the lateral line, and other counts which are of smaller scales to one side of the lateral line; Berg (1948-1949) gives a count of 80-97 for example, which is inherently more reasonable). Scales above the lateral line 12-17 and scales below the lateral line 16-24. Scales are incised on the anterior margin where about 6-9 radii terminate, although not as incised as in Perca fluviatilis. The focus is posterior. Ctenii are well-developed. First dorsal fin spines 11-17; second dorsal spines 1-4 and soft rays 16-27, usually 19-24. Anal fin spines 1-3, soft rays 9-14. Pectoral fin branched rays 11-18 and pelvic fin branched rays 5. Stubby, spinulose gill rakers number 10-17 and vertebrae 40-48, usually 45-48, mode 46. There are 4-9 pyloric caeca. The gut is relatively short but has a long anterior loop. The chromosome number is 2n=48 (Klinkhardt et al., 1995; Miri Nargesi et al., 2007) although the latter authors found a different karyotype formula in Iranian fish compared to other populations (2n=1m + 13sm + 4st + 6a).

Meristic values for Iranian specimens are:- lateral line scales 82(1), 86(1), 89(1), 90(1), 91(3); scales above the lateral line 13(1), 14(4), 15(1); scales below the lateral line 21(2), 22(1), 24(2), 25(1); caudal peduncle scales 33(3), 34(3); first dorsal fin spines 13(3), 14(4); second dorsal soft rays 20(2), 21(2), 22(1), 23(2); anal fin soft rays 11(4), 12(1) 13(2); pectoral fin branched rays 13(2), 14(2), 15(3); pelvic fin branched rays 5(7); and vertebrae 45(3) or 46(3).

Sexual dimorphism

Females have a much lighter, whitish belly than that of males which is marbled blueish in the spawning season. The genital papilla of females protrudes.

Colour

The back and flanks are green to blue-grey to brown-black, the belly is white to bluish and fins are yellow-grey. The dorsal and caudal fins have rows of black spots on the membranes, largest and most distinctive on the spiny dorsal fin. Other fins are pale yellow. The eye is silvery because of reflection from the tapetum lucidum. Young have 8-13 brown to blackish-brown bars but these usually fade with maturity. The peritoneum is silvery to brownish in preserved fish.

Size

Up to 1.5 m and 20.0 kg. The Iranian commercial catch in the 1950s was 24-60 cm long and weighed 1.6-2.7 kg, declining to 0.6 kg (Farid-Pak, no date).

Distribution

Found in the basins of the Baltic, Aegean, Black, Caspian and Aral seas. In Iran reported in the Aras River and along the whole Caspian coastal plain from Astara to the Atrak River including the Ameerkalaye Lagoon near Lahijan, the Gorgan, Qareh Su, Neka, Babol, Haraz, Safid and middle Aras rivers, as well as in the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea, Gorgan Bay, Anzali Mordab and Siah Keshim Protected Region (Nedoshivin and Iljin, 1929; Derzhavin, 1934; Kozhin, 1957; Griffiths et al., 1972; Holčík and Oláh, 1992; Nejatsanatee, 1994; Riazi, 1996; Abbasi et al., 1999; Kiabi et al., 1999; Abdoli, 2000; Jolodar and Abdoli, 2004; Abdoli and Naderi, 2009).

This species has also been stocked in the Zarreinerud, 70 km upstream of Miandoab in 1971 (Griffiths et al. (1972), to Valasht Lake near Marzanabad, Evan Lake northeast of Qazvin, Ghorigol Lake near Tabriz, Marivan Lake in Kordestan and the Haft Barm Lakes west of Shiraz (Anonymous, 1977). Although this species has been introduced to the Manjil Reservoir on the Safid River (Griffiths et al. (1972), this reservoir is drained to remove excess silt and no fishery exists (J. Holčík, pers. comm., 1992). Introductions to reservoirs in Khuzestan did not survive (M. Al-Mukhtar, pers. comm., 1995).

It is also found in the Karakum Canal and Kopetdag Reservoir of Turkmenistan (Sal'nikov, 1995) and may eventually reach the Iranian Tedzhen (= Hari) River basin.

Zoogeography

The relationships of this species are discussed under the genus.

Habitat

Generally this species is found in small schools near sandy and stony bottoms in deeper water of rivers. Ideally there should be some concealment. It can also live in reservoirs. This species has both freshwater and semi-anadromous forms in the Caspian Sea basin. It has a limited migratory behaviour such that morphologically distinct stocks may exist in larger water bodies. The population of the Anzali Mordab represents a separate stock (Hydrorybproject, 1965). Riazi (1996) and Karimpour (1998) report that this species migrates into the Siah-Keshim Protected Region of the Anzali Mordab and is also resident there. Most movements of this species are within 10-20 km although distances up to 300 km have been recorded in the Volga River. Suf show strong homing tendencies. The upper lethal temperature is 35°C. High turbidity levels are preferred. During the day, suf shelter from strong light by descending in the water column (Collette et al., 1977; Marshall, 1977). Knipovich (1921) reports this species from depths of 11.0-11.9 m, possibly deeper, in the Iranian Caspian Sea. In Dagestan this species prefers areas where there is flowing water well-supplied with oxygen (Shikhshabekov, 1978) and avoids vegetation and therefore competition with Esox lucius. Suf will tolerate low salinities and can be found around river mouths in the Caspian Sea basin but the sea itself is too saline.

Age and growth

Males mature at 2-6 years (32 cm) and females at 3-6 years (42-44 cm). Life span may exceed 19 years, although in Lake Eğirdir, Turkey only 7 age groups were recorded (Becer and Ikiz, 1999a). Optimum growth occurs at 28-30°C (Marshall, 1977).

During 1932-1933 in the Anzali Mordab, 5-7 year old fish dominated in catches and weighed 2.6-7.4 kg but by the 1960s this had declined to 2-5 years and 1.6-2.7 kg (Hydrorybproject, 1965). Catches in 1971/72 in the commercial fishery of Iran were 3-7 years old, 33.0-55.0 cm long and weighed 370-2100 g (Razivi et al., 1972). Abdolmalaki (2005a) found age groups in the Iranian Caspian to be 2-5 years with 2-3 year olds forming 78.5% of the catch. The von Bertalanffy growth equation was L_t = 52.5*[1-exp-0.158*(t + 1.852)]. The instantaneous rate of total, natural and fishing mortality was 0.95 year^-1, 0.31 year^-1 and 0.64 year^-1 respectively. The calculated exploitation ratio was 0.67, the estimated biomass was 31.56 tons, the minimum sustainable yield was 13.89 tons (lower than the total catch), and the fishery return coefficient was 2.87%. Abdolmalaki and Psuty (2007) report 6 age groups for coastal waters of the southern Caspian Sea, the length-weight relationship was w = -0.020606L^2.85, and the von Bertalanffy parameters were qeshm = 55.05 cm fork length (substantially less than in the Volga River delta at 79.0 cm and Aras Lake in Iran at 73.3 cm), K = 0.15, t₀ = -2.59 and M = 0.31. More than 90% of the beach-seine caught fish were smaller than the minimum legal length. These authors also provide details of recruitment and fishing mortality for this population which is enhanced by introduction of fingerlings. Rahimibashar et al. (2008) found that the fish in the Aras Dam lake had allometric growth and age classes caught with cast nets and gill nets were 2+ to 5+ years.

Food

The suf is an ambush-pursuit predator. Feeding on fish begins at a length of 5-10 cm (2-3 months of age) depending on the relative abundance of zooplankton, invertebrates and forage fish. In the Volga Delta, spawning Rutilus rutilus  (presumably R. caspicus) in April-May is the most important food, up to 80% of the annual ration. In the 1960s and 1970s when the population of suf was 7 million fish, they ate 53,000 tonnes of Rutilus rutilus (presumably R. caspicus) (Caspian Sea Biodiversity Database, www.caspianenvironment.org). Adults are solitary but young fish feed in schools on nauplii, copepods and some rotifers. Some adults are cannibals (Collette et al., 1977; Marshall, 1977; Popova and Sytina, 1977) and Balik (1999) reports that in Lake Beyşehir, Turkey, a suf can eat its own species with a mean size of 35.9% of its length. Apparently many prey fish are seized and swallowed tail first. One Iranian specimen contained a Neogobius melanostomus and gobies are an important food item generally in the Caspian Sea, 17.8% of the diet compared to 59.9% for Rutilus rutilus (presumably R. caspicus).

Rahimibashar et al. (2008) found that the fish in the Aras Dam lake were carnivorous, almost gluttonous, feeding principally on bony fishes (92% food preference) with some crab larvae and aquatic insects.

Reproduction

The spawning migration begins in late March-early April in Dagestan with spawning in early to mid-April (Shikhshabekov, 1978). In Eğirdir Lake, Turkey spawning took place from April to June and Becer and Ikiz (1999b) give details of fecundity, egg diameters, and the relationships between length, weight and gonad weight and fecundity for fish that mature as young as ages 1-2. The spawning season over the range of this species is late February to late July, usually April-May at 12°C (range 6-22°C) as deep as 17 m. There are distinct spawning stocks.

In the Anzali Mordab, the main spawning area in the southern Caspian, the spawning run usually starts in the first 10 days of March at water temperatures of 8.0-9.5°C, ending at 12-14°C (Hydrorybproject, 1965; Razivi et al., 1972). Apparently, natural spawning has stopped completely in the mordab and this lagoon is stocked with fingerlings from spawners held at Aras, a border reservoir lying between Iran and Azerbaijan (Abdolmalaki and Psuty, 2007). Males build nests in depths of 30 cm to several metres on hard bottoms usually in turbid water. Each nest is a flat pit edged by gravel or shell. Plant roots are often exposed as a spawning substrate on which eggs are laid individually. The nest is guarded by the male and eggs are fanned. The female is driven away after spawning. Male suf are so devoted to protecting the nest that they will remain on site even if water levels fall and their backs stick out of the water. In addition they will try to bite humans if they approach the nest. Spawning is intermittent over several days and usually takes place at dawn. Maximum fecundity is 2.5 million eggs and egg diameters are up to 1.5 mm. Hatching occurs from 4 to 26.5 days, depending on temperature (Collette et al., 1977; Marshall, 1977). Females descend to the sea first from the Anzali Mordab after spawning and fry there are 19-33 mm long by the end of May (Hydrorybproject, 1965).

Parasites and predators

Eslami and Mokhayer (1977) examined 100 specimens of suf and found 20% to be infested with larvae of the nematode Anisakis. Ataee and Eslami (1999, www.mondialvet99.com, downloaded 31 May 2000) report the helminth Anisakis from the gastro-intestinal tract of fish from the Anzali wetland. This parasite can infest man if fish is eaten smoked, salted or fried at temperatures below 50°C. Mokhayer (1976b) records the acanthocephalan Corynosoma caspicum. Jalali and Molnár (1990a) record the monogenean Ancyrocephalus paradoxus from this species in the Safid River. Masoumian et al. (2005) recorded the protozoan parasite Trichodina perforata from this species in the Aras Dam in West Azarbayjan. Pazooki et al. (2007) recorded various parasites from localities in West Azarbayjan Province, including Diplostomum spathaceum and Argulus foliaceus from this species. Barzegar et al. (2008) record the digenean eye parasite Diplostomum spathaceum from this fish. Barzegar and Jalali (2009) reviewed crustacean parasites in Iran and found Achtheres percarum on this species.

The Caspian seal, Pusa caspica, is a significant predator on this species (Krylov, 1984) as are predatory fishes such as Esox lucius, Perca fluviatilis and Silurus glanis. Adult suf have few predators.

Economic importance

There is some opportunity for sport fishing for this species in the Anzali Mordab and potentially in various lakes around the country where it has been introduced (Anonymous, 1977). It is a very popular food fish in Iran (Razivi et al., 1972). It has also been studied in Iran as a control species for undesirable fishes (Annual Report, 1995-1996, Iranian Fisheries Research and Training Organization, Tehran, p. 80, 1997).

Nevraev (1929) reports on catches in various regions of Iran in the early years of the twentieth century. There were no evident trends of increase or decrease. In the Astara region from 1901-1902 to 1913-1914 the catch varied irregularly from 154 to 31,931 fish, in the Anzali region from 1901-1902 to 1918-1919 the catch varied from 608,300 to 3,367,000 fish, in the Safid River region from 1899-1900 to 1917-1918 the catch varied from 9983 to 125,182 fish, and in the Astrabad region from 1900-1901 to 1912-1913 the catch varied from 1400 to 22,900 fish.

Stocks of this species are known to fluctuate in Iran, as obviously do the catch statistics. Most fish are caught in beach seines although some are caught in gillnets, both legally and illegally (see below). The main fishing ground is coastal waters in the Anzali region. Catches in the 1920s were at 3000-4000 tonnes for the coastal zone of the southern Caspian Sea but declined drastically afterward (Razavi, 1999). The commercial catch in Iran from 1956/1957 to 1961/1962 varied from 206 kg to 20,945 kg (Vladykov, 1964; RaLonde and Walczak, 1972), from 1965/66 to 1968/69 it varied from 7 to 77 tonnes (Andersskog, 1970) and from 1963 to 1967 ranged from 0 to 14.6 t (RaLonde and Walczak, 1970b). In the 6 years from 1980 to 1985 catches were recorded by the Food and Agriculture Organization, Rome as respectively 0, 0, 0, 12, 13 and 10 t. Catches in 1990 were about 5-10 t and in 1996 about 35-40 t (Bartley and Rana, 1998b). In 2000-2001, the catch was 18 t or 11% of the total commercial catch in the Iranian Caspian Sea basin. 12 t were caught by beach seine along the coast, 3 t were taken in the Anzali Mordab and the rest was an estimated amount of unlicensed captures (Abdolmalaki, 2005a). In 2003-2004 the catch was 38 t, a decrease in comparison to the previous year, with 15 t of this from beach seine cooperatives. Most fish were immature and undersized and the catch was based on release of fingerlings (Abdolmalaki, 2006).

Summaries of catches of this species in the coastal southern Caspian Sea over 8 decadal periods is given in Fisheries. Recent catches from Abdolmalaki and Psuty (2007) are as follows:-

Year	Total catch (t)	Catch by beach seine (t)	Number of beach seine cooperatives	Beach seine efforts (hauls)	Number of illegal gillnets confiscated
1990	4.0	4.0	68	20.975	No data
1991	12.3	12.3	81	27,200	104,828
1992	10.0	8.7	88	30,239	109,446
1993	12.3	7.3	93	33,986	138,026
1994	40.2	22.6	91	27,868	215,381
1995	10.1	4.0	101	34,055	204,831
1996	8.0	2.8	109	42,847	270,727
1997	8.1	2.9	111	45,263	205,999
1998	95.0	54.8	125	52,574	222,897
1999	17.5	11.5	139	50,953	130,849
2000	18.0	12.0	147	56,913	82,678
2001	26.0	21.5	150	60,006	113,729
2002	30.0	20.3	150	57,310	141,506
2003	23.8	15.0	151	53,846	179,656
2004	22.5	14.4	151	49,809	261,875

In the period from 1933/34 to 1961/62 in the Bandar-e Anzali region catches varied from about 3483 t at the earlier date to 33 kg at the later one, with large variations between years. Holčík and Oláh (1992) report a catch of only 22 kg in the Anzali Mordab in 1990, and from 1932-1964 reported catches varied from 1 to 2581 t annually.

Hedayatifard and Jamali (2008) showed that this fish is a good source of polyunsaturated fatty acids and one of the best sources for omega-3 fatty acids, useful in preventing cardiovascular disease.

Khaval (2007) investigated polyculture of this species with silver, bighead, grass and common carp at the Safidrud Fisheries Research Station. Carp density was 3000 fish per hectare with 60% silver carp, 20% grass carp and 10% each for common and bighead carp. Suf weighed 2.1 g and were stocked at 250 fish per hectare. Survival rates were 93.33% for the suf and 83.77% for the Chinese carps. Over the period April to November, suf fingerlings reached 54.4 g on average and production was 4446.66 kg per hectare compared to 3212.8 kg without polyculture. Ghafouri Salah et al. (2008) studied physiological stress in this species and its effects on cortisol and muscle compounds.

Robins et al. (1991) list this species as important to North Americans. Importance is based on its use in aquaria and aquaculture, as food, in sport, in textbooks, and because it has been widely introduced outside its natural range. The suf or pike-perch is also fish-farmed in Europe for stocking purposes as eggs or young.

Conservation

The decline in catches from about 3000-4000 tonnes to about 30 t noted above has never been adequately explained. Overfishing, degradation of spawning grounds, fluctuating water levels and salinity variations in coastal waters, the volume of freshwater input, oxygen concentrations and input of organic material to estuaries and the sea, are all possible factors (Abdolmalaki and Psuty, 2007). The stocks of this species in Iranian waters also declined in the 1960s (Walczak and RaLonde, 1970; RaLonde and Walczak, 1972). Causes were reduction in estuarine habitat needed for spawning, man-made habitat changes and overfishing of the younger age classes and first year spawners. The catch declined from 125 tonnes annually in the 1940s to 14.6 t in 1967. Vladykov (1964) considered stocks all along the Iranian shore to be at dangerously low levels. Griffiths et al. (1972) suggested that stocks in Iran were on the verge of extinction and recommended a three-year ban on catching this species. Artificial raising of this species is difficult but more than 6 million fingerlings were raised and released into the Anzali Mordab in the Iranian year 1991-1992, a 100% increase over the previous year (Abzeeyan, Tehran, 4(2):VI, 1993). Fingerling production rose from 0.12 million in 1990, to 1.50 million in 1991 and 2.50 million in 1992 (Emadi, 1993a)(note that Matinfar and Nikouyan (1995) give 1.63 and 2.44 million fingerlings for 1991 and 1992). Fingerling production in 1995 was 2.269 million, in 1996 2.4 million and for 1996-1997 8 million (Bartley and Rana, 1998a; 1998b). The Sturgeon International Research Institute, which opened in 1994 near Rasht, released 5-8 million fry in 1996-1997 (Bartley and Rana, 1998b). The release in 1999 numbered 5 million "juveniles" (I.F.R.O. Newsletter, 23:4, 2000). Billard and Cosson (2002) cite an annual production of 5-10 million, mostly released in the Anzali lagoon and Moghaddam (2006) gives a figure of 5.13 million fingerlings for 2002. The highest number of fingerlings released in the Anzali Lagoon was 6,604,000 in 2003 with the lowest being 1,160,000 in 1993 for the period 1991-2003 according to Abdolmalaki and Psuty (2007). The latter authors also note that the beach seines used in Iran (see Fisheries in Introduction) do not protect young fish. There is a heavy mortality of discarded fish even when legal landing size is enforced and resources are inadequate to manage the fishery effectively. The minimum mesh size of the cod-end of the seines should be increased and its use monitored.

Ramin (1996) has studied semi-artificial propagation and rearing of fry of this species in Iran. Broodstock spawning occurs in March-April at 12-14°C on artificial nests of green wool bunches on wooden frames placed in ponds at 5 m intervals. Nests close to the bottom are preferred and eggs are dropped on them with an average fertilization of 30-90%. The nests with eggs on them are kept in a mist chamber and the eggs collected and placed in jars. Eyed eggs appear on day 3 or 4 of incubation. Yolk-sac absorption lasts 9-13 days and exogenous feeding fry measure 4-6 mm.

Lelek (1987) classifies this species as intermediate to vulnerable in Europe. Kiabi et al. (1999) consider this species to be vulnerable in the south Caspian Sea basin according to IUCN criteria. Criteria include commercial fishing, sport fishing, few in numbers, limited range (less than 25% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin. Nezami et al. (2000) consider this species to be endangered because of overfishing, habitat destruction and spawning ground degradation.

Further work

The numbers of this species should be actively surveyed because of threats outlined above.

Sources

Deelder and Willemsen (1964) reviewed the biology of this species as did Craig (1987). Robins (1970) gave a bibliography of the genus Stizostedion (= Sander).

Iranian material: CMNFI 1970-0532, 1, 209.3 mm standard length, Gilan, Caspian Sea near Bandar Anzali (37º28'N, 49º27'E); CMNFI 1979-0431, 2, 211.5-241.0 mm standard length, Mazandaran, Now Shahr fish bazaar (no other locality data); CMNFI 1979-0455, 1, 68.5 mm standard length, Markazi, Manjil Dam (36º45'N, 49º17'E); CMNFI 1980-0127, 1, 266.1 mm standard length, Gilan, Caspian Sea near Hasan Kiadeh (37º24'N, 49º58'E); CMNFI 1980-0130, 1, 197.4 mm standard length, Mazandaran, river near Iz Deh (36º36'N, 52º07'E); CMNFI 1980-0150, 1, 280.8 mm standard length, Gilan, Caspian Sea at Safid River estuary (37º24'N, 49º58'E).

Sander marinus
(Cuvier, 1828)

Common names

suf-e daryai (= sea suf), souf-e-daryaee.

[daniz sifi in Azerbaijan; morskoi sudak or sea pike-perch, erroneously bërsh by fishermen in the Caspian Sea, both in Russian; sea zander, estuarine perch].

Systematics

Lucioperca marina was originally described from the Black Sea at Feodosiya. No types are known (Eschmeyer et al., 1996).

Key characters

This species is distinguished from S. lucioperca by the dorsal fins being well-separated, but by a distance less than eye diameter, anal fin spines are weak and closely joined to the soft rays, interorbital width in adults is much greater than eye diameter, the upper jaw extends back level with the posterior pupil edge or almost to the posterior eye edge in adults, the dorsal fin soft rays are 18 or less, and the spiny dorsal fin lacks large spots.

Morphology

First dorsal fin spines 12-14, second dorsal fin spines 1-4 followed by 12-18 soft rays, anal fin spines 2-4 followed by 9-12 soft rays, pectoral fin with 1 spine and usually 15 soft rays, and pelvic fin with 1 spine and 5 soft rays. Lateral line scales 75-88, scales above the lateral line 9-13 and caudal peduncle scales 34-36. Scales have few anterior radii, a crenulate anterior margin and a posterior focus. Gill rakers on the upper arch number 12-20, on the lower arch 11-17, reaching the second raker below when appressed, elongate and spinulose. Vertebrae number 38-44. There are 5-7 pyloric caeca. Cheeks are scaleless or almost scaleless. There are canines on the jaws and palatines. These counts are combined for several literature sources and include eastern and western populations of the southern Caspian Sea which show evident differences indicating distinct stocks. The gut is short and s-shaped.

Meristic values for Iranian specimens are:- first dorsal fin spines 13(2) or 14(1), second dorsal fin spines 2 (3), soft rays 16 (3); anal fin spines 2(3), soft rays 12(3); soft pectoral rays 15(3), pelvic fin with 1(3) spine and 5(3) soft rays, lateral line scales 79(2) or 82(1), scales above lateral line 10(1), 12(1) or 13(1), caudal peduncle scales 34(2) or 36(1); and total gill rakers 12(1), 13(1) or 15(1).

Sexual dimorphism

Unknown.

Colour

The back is light grey and the flanks have 12-15 dark bars, which are sometimes indistinct and may be absent, e.g. in females from the eastern Caspian which had small, irregular, dark-brownish speckles. Some fish are almost black and lack bars. The first dorsal fin lacks the strong spots seen in Sander lucioperca and is dark grey to black with patches of concentrated melanophores and clearer areas forming irregular and incomplete stripes, or darkly fringed and with a dark spot at the posterior base. The second dorsal fin and the caudal are finely spotted. Other fins are grey with some melanophores on rays. Eyes are silvery due to the tapetum lucidum. The peritoneum is brownish.

Size

Attains 62 cm (65 cm total length in Jolodar and Abdoli (2004)) and 2.2 kg.

Distribution

Found only in the northwestern Black Sea and the Caspian Sea. Reported from near Gasan-kuli in Turkmenistan (Berg, 1948-1949) and from the southeast Caspian Sea in Iran (Kiabi et al., 1999). Jolodar and Abdoli (2004)  and Abdoli and Naderi (2009) record it from the central, southwestern and southeastern regions of the Caspian Sea including in Astara. An old record is cited below under Habitat.

Zoogeography

The relationships of this species are discussed under the genus.

Habitat

This species lives in the Caspian Sea proper and rarely enters rivers. De Filippi (1865), however, did record "Un molto bello e grosso individuo....in un canale di Murdab, ove l'aqua era del pari sensibilmente dolce". It favours areas with rocky bottoms and does not migrate. In winter, part of the population moves into deeper water at depths of 30 m, rarely 100 m, while another part remains near the shore. The major concentration of this pike-perch is found near the shores of Turkmenistan, and secondly of Azerbaijan.

Age and growth

Sexual maturity is attained at 3-4 years for most fish with a few fish maturing at 2 years (Guseva, 1975). Life span is at least 12 years. Growth is slightly faster in females up to age 5, evens out later and males become larger (Kuliyev, 1981). Males on the spawning grounds average 41.2 cm and females 42.9 cm, with an average weight of 0.94 kg (Berg, 1948-1949).

Food

The principal foods are gobies (Gobiidae), young herring and tyulkas (Clupeidae), silversides (Atherinidae), and crayfish.

Reproduction

The male prepares a nest site and protects the eggs. Spawning takes place at 3-12 m on open, stony bottoms or in "nest-caves" and eggs are laid in a continuous layer. The male constructs and guards the nest. Spawning usually begins in the second half of April and ends in mid-May at temperatures of 10-17°C, and is most intense at 13-15°C (Gusev, 1974a). Up to 126,000 adhesive eggs are laid (Guseva, 1974a; 1975; Kuliyev, 1981) and are larger than in S. lucioperca. Fertilised eggs are 2.6-3.8 mm and at water temperatures of 14.7°C, incubation takes 12-17 days (Gusev, 1974a).

Parasites and predators

None reported from Iran.

Economic importance

The sea pike-perch was commercially fished off the Turkmenistan coast in the 1930s and 1940s with catches of 19 thousand centners (1 centner = 100 kg) or 2,271,000 fish. In 1927-1929 the annual average on the shores of Azerbaijan was 7000 centners and in 1930-1932 10,3000 centners. In 1930 the catch for the whole Caspian Sea was 909 thousand centners (Zenkevitch, 1963). The development of offshore oil deposits has drastically reduced stocks throughout the Caspian Sea (Guseva, 1974b; 1975; Kuliyev, 1981).

Robins et al. (1991) list this species as important to North Americans. Importance is based on its use in textbooks.

Conservation

This species has been proposed for inclusion in the "Red Book of the U.S.S.R." which forms the basis for measures to protect species (Pavlov et al., 1985). Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include possibly few in numbers, limited range (less than 25% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin. The 2000 IUCN Red List lists this species as DD (Data Deficient).

Further work

The distribution and abundance of this species in Iranian waters needs to be examined to determine its conservation status.

Sources

Morphology based in part on Svetovidov and Dorofeeva (1963) and Kuliyev (1981).

Iranian material: CMNFI 1970-0532, 3, 156.3-165.5 mm standard length, Gilan, Caspian Sea near Bandar Anzali (37º28'N, 49º27'E).

Sparidae

The sea breams or porgies are found in the Atlantic, Indian and Pacific oceans and comprise about 36 genera and about 130 species (Nelson, 2006; Eschmeyer and Fong, 2011). Some commonly enter estuaries and penetrate up rivers. Maximum length is about 1.2 m.

This family is characterised by a groove in the distal end of the premaxilla which accommodates the maxilla; the body is oblong to ovate and is compressed; the head is large with a steep upper profile; the preopercle margin is smooth; scales are weakly ctenoid, moderate in size and extend on to the cheeks and operculum; teeth are conical to incisiform and molar teeth are found in some at the rear of the jaw; there are no teeth on the vomer, palatines or tongue; the dorsal fin is continuous with an anterior spiny portion and a soft-rayed posterior portion about equal in size; with 10-13 spines and 10-15 soft rays respectively; spines fold into a groove; the anal fin has 3 spines (the second the largest) and 8-14 soft rays; branchiostegal rays 5-6; branchiostegal rays 5-6; and lateral line not continued onto the caudal fin but with enlarged scales near the head.

Many species in this family are hermaphrodites with male and female sex organs developing simultaneously, changing sex from male to female (protandry), or from female to male (protogyny). These fishes are often important as food or sought by anglers. Young fish may very different in colour to adults, usually being more vividly coloured with distinctive patterns. Most species are marine (see Marine List in Checklists in the Introduction) but a few enter fresh water and penetrate a considerable distance from the sea including one species in Iran.

Genus Acanthopagrus
Peters, 1855

Members of this genus have a compressed and moderately deep body, 4-6 enlarged incisiform teeth at the front of the jaws followed by 3-4 rows of molars, the second anal fin spine is longer than the third, there is a scaly sheath at the base of the dorsal and anal soft fins, and moderate-sized scales. Iwatsuki and Heemstra (2010) revised the genus in the western Indian Ocean.

Acanthopagrus latus
(Houttuyn, 1782)

Common names

شانك (= shanak), شانك زردباله (= shanak-e zardbaleh or yellowfin shanak).

[shanak, shaghoom, shaam, sha'm, shaem, sheim or sha-om in Arabic; yellow-finned porgy or seabream, yellow-finned black porgy, Japanese silver bream].

Systematics

Sparus latus was originally described from Japan.

Al-Hassan (1990) found differences in two meristic characters (pectoral and dorsal fin ray counts) but no differences in electrophoretic characters between populations from the Shatt al Arab and Khor al Zubair areas of southern Iraq. He concludes that there is only one stock of this species in southern Iraq as meristic variation may reflect environmental conditions.

Key characters

This species is the only sparid member recorded from Iranian freshwaters and is recognised by the dorsal fin spines alternately thick and thin and the colour pattern.

Morphology

Upper profile of head steep and convex back to above the posterior eye margin. The head bulges over the eye. Dorsal fin spines 11-13, soft rays 9-13. Anal fin with 3 spines, the second much stronger and wider than the third, and 8-9 soft rays. Pectoral fin branched rays 10-16. There is a strong spine in the pelvic fin and a well-developed axillary scale. Lateral line scales 41-46, or 48-50, or up to 55 depending probably on differing counting methods. The scales are vertical ovals with the anterior margin wavy where radii intersect. They have very fine circuli, moderate numbers of posterior radii, a subcentral posterior focus, and ctenii on the central part of the posterior margin extending inwards towards the focus. Four or five series of preopercular scales. The first pelvic fin ray is elongated as a small filament. There is a strong pelvic axillary scale. There are 3-4 scale rows sheathing the dorsal and anal fin bases. There are 4-6 compressed teeth in front of each jaw followed by 3-5 rows of molar teeth. The chromosome number is 2n=48 (Klinkhardt et al., 1995). The gut is an elongate s-shape.

Meristic values for Iranian specimens are:- dorsal fin spines 12, soft rays 10, anal fin spines 3, soft rays 8, pectoral fin branched rays 13, scales mostly lost.

Sexual dimorphism

This species is a protandrous hermaphrodite, being male early in its life and then becoming female later. Catches will include males, females and hermaphrodites, e.g. in Abu-Hakima's (1984a) study in Kuwait, there were 326 males, 343 females and 41 hermaphrodites.

Colour

Overall colour is a silvery-grey or silvery-white with the back darker and the belly yellowish. Scales each have a dark, brownish to golden spot at the base which line up to form apparent stripes along the flank. There is a dark blotch at the upper corner of the gill opening, on both the body and gill cover. There is a dark band over the head between the eyes and the edge of the operculum is dark. Dorsal fin spines are white and the membranes are grey, with dark margins between the spine tips. The soft dorsal fin is dark grey with a light orange tinge. There is a small back spot at the pectoral fin base and the fin is mostly hyaline with a light orange tinge. The anal and pelvic fins are a light yellowish-brown. The caudal fin is dark grey on the upper lobe and yellow on the lower with a black margin. The peritoneum is silvery brown in preserved fish with widely scattered melanophores.

Size

Reaches over 50 cm total length.

Distribution

Found from the Persian Gulf to Japan and north Australia. Recorded from the Helleh River in Bushehr Province, Iran (J. Holčík, pers comm., 1995), from the Bahmanshir River (Marammazi, 1995; Eskandary et al., 1999) and from Mahshahr creeks in the northwest Persian Gulf such as Jafari, Ghazaleh, Majidieh Petroshimi and Zangi, which are polluted (Savari et al., 2010, 2011; Movahedinia et al., 2011). Also from the Shatt al Arab in Iraq on the border with Khuzestan in Iran (Al-Hassan et al., 1989; Hussain et al., 1989).

Zoogeography

This marine species enters rivers in southern Iran and presumably freshwater stocks are maintained from this marine gene pool.

Habitat

The usual habitat is over sand and rock bottoms in the sea down to about 50 m, but young fish may enter estuaries and may penetrate considerable distances inland, although some fish remain at sea permanently. The frequency of penetration into Iranian rivers along the Persian Gulf coast is not known. Larger specimens are known to penetrate the Shatt al Arab in autumn, October to December, and this water body is an important nursery for this species, found there year round as young. Adults emigrate from January to March (Al-Hassan, 1990; Hussain et al., 1987). At a freshwater station on the Shatt al Basrah Canal with salinities up to 3.5‰, Al-Daham and Yousif (1990) found this species to be the second most dominant after Liza subviridis, comprising 7.1% by number and 10.9% by weight. Al-Daham et al. (1993) found young fish in the Shatt al Basrah mostly from April to October. Cage-cultured fish are reared at 14-31°C in Kuwait Bay (Abou-Seedo et al., 2003). Temperatures in Kuwait Bay during spawning are 14-18ºC during the winter months, a situation mirrored by Liza klunzingeri but not other species which begin to spawn in April (Abou-Seedo and Dadzie, 2004). Savari et al. (2010) showed that enzymatic indices could be used to evaluate ecological features and as biomarkers for pollution, Savari et al. (2011) showed that blood abnormalities and haematological parameters can be indicative of pollutants, and Movahedinia et al. (2011) showed that hormones could also be used in this regard.

Age and growth

A fast growing and hardy fish. Life in Iranian fresh waters has not been studied and information is about marine or estuarine populations.

Colour photographs of males (females in background) courtesy of Thomas Schulz

Spawning site photographs courtesy of Thomas Schulz

Parasites and predators

Piscivorous birds have been observed along the streams where the cichlid is found. Ansary et al. (2010) record the anisakid nematodes Contracaecum sp. and Phocanema sp. from this fish in the Mehran River.

Economic importance

Saadati (1977) suggests that this salt-tolerant species could be a valuable resource if introduced into the saline and fishless waters of internal basins. However this is not advisable since the native fauna, evolved in a fishless environment, could be devastated before it has even been documented. Esmaeili et al. (2009) note that it is eaten by local people when available in large numbers in spring. It is now an aquarium fish in Germany (Schulz, 2002; 2004a; 2004b; Oliver Lucanus, pers. comm., 23 January 2004; Lamboj et al., 2006; Svardal, 2006; Svardal and Svardal, 2006) and juveniles sell for about $80 each (www.fishlore.com/fishforum/freshwater-beginners/67104-see-any-steals.html, 21 March 2010). Articles in aquarium magazines give photographs in spawning condition, including mouth-brooding, and details for their maintenance, including water with a conductivity of 50-70mS/cm NaCl or sea salt mixture, tank water changed once a week, vegetarian food tabs (containing the blue-green alga Spirulina), and a temperature of 20-35°C, optimally 27°C. It has been noted that males, in continually defending a nest and courting, "wear out" earlier than females (Thomas Schulz, in litt., 12 October 2006).

Conservation

Axelrod (1993) states that "as pollution chokes the waters of southern Iran, we can expect this fish to disappear very quickly" and "Because of the restricted range of this fish and the continual warfare and oil pollution in the area, Iranocichla hormuzensis may well be on its way to extinction - if it is not gone already". Bailey (2006) apparently repeats this. However its habitat is mostly saline streams which cannot readily be used for agriculture or industry. The surrounding area is not industrialised, nor likely to be, and was never a war zone so pollution is not a problem for this species.

Flash floods are probably a significant problem as water drains rapidly off vegetation barren land. The scouring action may well displace or strand cichlids. Mouth brooding offers protection against floods and against associated fishes.

Svardal (2006) and Svardal and Svardal (2006) give details of capture, transport and aquarium care of this species.

Further work

Further investigations into the biology of this species are needed.

Sources

Rabbaniha (1993a, 1993b, 1994) gives Farsi accounts of this species and cichlids in general. The account is based principally on Coad (1982a).

Type material: See above, CMNFI 1979-0408A, CMNFI 1979-0408B, CMNFI 1979-0139, BM(NH) 1981.1.12:1-2,  MNHN 1981-107, 108, CAS 47324, ROM 36389 and BC 81-1.

Iranian material: CMNFI 1979-0138, 17, 25.6-97.3 mm standard length, Fars-Hormozgan border, stream in Rasul River drainage (ca. 27º32'N, ca. 54º58'30"E); CMNFI 1979-0140, 48, 24.2-59.4 mm standard length, Hormozgan, stream east of Kichal, Kul River drainage (27º14'N, 55º46'30"E); CMNFI 1979-0141, 5, 15.0-21.0 mm standard length, Hormozgan, Kul River (27º17'30"N, 56º03'30"E); CMNFI 1979-0142, 65, 21.3-82.8 mm standard length, Hormozgan, Baghu River (27º17'N, 56º28'E); CMNFI 1979-0143, 3, 25.0-26.7 mm standard length, Hormozgan, marsh in Hasan Langi River drainage (27º21'N, 56º50'30"E); CMNFI 1979-0148, 5, 33.2-92.7 mm standard length, Hormozgan, Sarzeh River (27º30'30"N, 56º15'30"E); CMNFI 1979-0181, Hormozgan, Kul River (27º17'30"N, 56º03'30"E); CMNFI 1979-0184, 12, 31.4-50.4 mm standard length, Hormozgan, effluent of Rasul River (27º11'N, 55º42'E); CMNFI 1979-0185, 7, 26.1-59.8 mm standard length, Hormozgan, stream in Rasul River drainage (27º06'N, 55º45'E); CMNFI 1979-0187, 2, 63.9-64.6 mm standard length, Hormozgan, stream at Sar Khun (27º23'30"N, 56º26'E); CMNFI 1979-0406, 5, 33.4-59.2 mm standard length, Hormozgan, stream north of Bandar-e Charak turnoff (26º48'N, 54º18'E);CMNFI 2007-0053, 17, 28.0-59.9 mm standard length, Hormozgan, Sarzeh River (ca. 27º36'N, 56º15'E); CMNFI 2007-0057, 14, 30.2-85.5 mm standard length, Hormozgan, Mehran River below Bastak (ca. 27º05'N, ca. 54º05'E); CMNFI 2007-0058, 2, 64.8-83.0 mm standard length, Fars, headwaters of Gowdar River (ca. 27º24'N, ca. 54º16'E)

Genus Oreochromis
Günther, 1889

Oreochromis niloticus
(Linnaeus, 1758)

Introduced to the Tigris River basin in Iraq but did not apparently survive winterkill (Herzog, 1969). Mutlak and Al-Faisal ( 2009), however, record O. aureus (possibly O. niloticus) from Basrah in southern Iraq and this species could easily become established in Iran. No Iranian record confirmed as yet. Red tilapias (Oreochromis sp.) have been studied in aquaponic systems in Iran so there is a potential for an exotic release (Rafiee and Saad, 2005). Fingerlings from Indonesia have been reared using saline waters at Bafgh, Yazd Province in 3 ton fibreglass tanks. Larvae were successfully grown to 2.0 kg at 28±1ºC (Iranian Fisheries Research Organization Newsletter, 57:2, 2009).

Genus Tilapia
Smith, 1840

Tilapia zilli
(Gervais, 1848)

Introduced to the Tigris River basin in Iraq but did not apparently survive (Job, 1967). Redbelly tilapias are established in the Syrian Euphrates (R. Beck, pers. comm., 2000) and a recent report by Beshar Abd Al-Hussain Al-Saadi (in litt., 10 October 2006) of a cichlid at Al Musayyib on the Euphrates River in Iraq may well be this species. Mutlak and Al-Faisal ( 2009), record this species from Basrah in southern Iraq and these could spread to Iranian waters. No Iranian record as yet. The Farsi name is تيلاپيا (= tilapia).

Gobiidae

The gobies are a world-wide family found mostly in warmer marine waters although some species enter fresh water and others live there permanently (see also Marine List in Checklists in the Introduction). The number of species is high and this may be the most speciose fish family in the world with about 248 genera and about 1630 species, perhaps more (Eschmeyer and Fong, 2011). A diversity of gobies occurs in the Caspian Sea basin. Not all Caspian gobies have valid Iranian records but most will probably be found there. Several gobies penetrate southern waters of Iran from the Persian Gulf and Sea of Oman and are described here. Others will probably be discovered when more detailed surveys are made.

Gobies are easily distinguished by their pelvic fins being united as an adhesive or sucking disk or cup. Body form and coloration are diverse. The pattern of head canals, canal pores and neuromasts is distinctive and used in identifying and relating species (except in "Neogobius" (Pinchuk, 1991)). However the neuromasts may be sunken in narrow furrows or pits and completely covered by epithelium so they do not preserve well and this can lead to confusion in identifications (Zambriborshch, 1968). There is usually a short spiny dorsal fin (2-8 flexible spines) separated from, but close to, a soft dorsal fin. The soft dorsal fin and anal fin are longer than the caudal peduncle. Scales may be cycloid, ctenoid or rarely absent. No obvious lateral line. There are 5 branchiostegal rays. Gill membranes are connected to the isthmus and gill openings are moderate to wide, or very restricted in the mudskippers. The head is usually blunt and the mouth is usually large. Teeth are usually small and conical in one to several rows in both jaws. Miller in Miller (2003) gives a suite of osteological characters defining the family.

Most gobies are quite small (5-10 cm) and they are often very abundant. Maximum size is about 50 cm. Some of the world's smallest vertebrates are gobies from the Indian Ocean, mature at 8 mm. Others, however, are large and form part of fisheries in both the Caspian Sea and the Indian Ocean. They are not significant food fishes in Iran. Gobies tend to rest on the bottom and move in sudden, characteristic dashes. The male goby guards a nest. Food is crustaceans, worms, molluscs and small fishes. Many gobies are important in the aquarium trade since they are beautifully coloured, small and tough.

They are known generally as gav mahi (= cow fish) or sag mahi (= dog fish) or contain the word gel (= mud) in Iran. A general review in Farsi of the Caspian gobies is given by Aslaanparviz (1991).

The males of some Caspian species become black during the spawning season, their fins elongate, head shape alters and some even become naked. Loss of tubercles in adult male gobies of the genus Benthophilus makes it possible to identify only juveniles and females. The males build nests and guard the eggs. Life span of certain Caspian species is said to be as short as one year, e.g. some species of Benthophilus, Knipowitschia, and Proterorhinus. Neogobius pallasi, N. melanostomus and Ponticola gorlap consume the invasive ctenophore, Mnemiopsis leidyi, as much as 10-15% of total biomass in some areas (Mamedov, 2006).

The Black and Caspian Sea basins contain an endemic Sarmatian fauna of gobies. There are two main clades, the gobiine-benthophilines (or transverse gobiids) and the pomatoschistines (or sand gobies), that have probably been distinct for at least 40 million years. Miller (2001) and Miller in Miller (2003) reviews the evolutionary history of these two clades and their anatomical differences based on head papillae and osteology. The transverse gobiids include Mesogobius, Neogobius, Proterorhinus, Chasar, Anatirostrum, Benthophiloides, Benthophilus and Caspiosoma while the sand gobies include Knipowitschia and Hyrcanogobius. The Sarmatian fauna was separated from the Atlantic-Mediterranean fauna with the isolation of the Paratethys during the late Miocene Messinian salinity crisis as the Mediterranean dried. Partial flooding of the Mediterranean from the Paratethys in the early Pliocene allowed Sarmatian gobies to spread westwards. Within the Ponto-Caspian basin, evolution of species flocks was favoured by basin sub-divisions and rejoinings. The benthophilines may be a monophyletic group from these events.

Ahnelt and Duchkowitsch (2004) give information on the neogobiine stock. About 12-13 million years ago in the Middle Miocene, the Ponto-Caspian endemic and ancestral neogobiine stock may have differentiated from an Atlantic-Mediterranean gobiine stock. At this time the Paratethys was a sea with reduced salinity and a high level of endemism. The Neogobius-Proterorhinus stock developed independently from the recent Gobius stock that invaded the Mediterranean basin after that sea was restored about 5 million years ago in the Late Miocene.

Neilson and Stepien (2009a) using mitochondrial and nuclear genes detail the evolution and biogeography of the subfamily Benthophilinae restricting Neogbius to caspius, melanostomus and pallasi with other known Iranian species formerly in Neogobius placed in Ponticola. The Benthophilinae includes Babka, Mesogobius, Neogobius, Ponticola and Proterorhinus as well as the tadpole gobies (Anatirsotrum, Benthophiloides, Benthophilus and Caspiosoma). The origin of the genera Babka, Benthophilus, Caspiosoma, Mesogobius, Neogobius, Ponticola and Proterorhinus ranges from 4.29 to 6.25 MYA and the paper gives divergence times for major lineages in relation to geological events in the Ponto-Caspian. These events include connections with, and isolation from, the World Ocean and salinity changes in a range of 1-30 p.p.t. over the last 5 million years. Most genera diversified about 5 MYA when the Black and Caspian seas separated. More recent separation events occurred during the Pleistocene glaciations Proterorhinus diverged from Mesogobius about 6.18 MYA, the Ponticola clade diverged about 4.51-4.86 MYA, and freshwater Proterorhinus emerged 1.18 MYA.

The principal recent works on the systematics of Caspian gobies are by V. I. Pinchuk, D. B. Ragimov, Ye. D. Vasil'yeva, H. Ahnelt and P. J. Miller. Earlier works are by B. S. Iljin (also spelled Il'in or Ilyin). Later molecular studies are cited above.

Other gobies in Iran are the familiar tropical mudskippers which can move quickly over land, using the muscular-based paired fins to row across mud, and some can even clasp and climb mangroves. They can live out of water because the gill openings are small to prevent desiccation of the gills, oxygen can be taken into the chamber and absorbed through the gills and chamber wall, and they can also absorb oxygen through their skin. They often rest with the tail immersed in water for this purpose or roll around in shallow water to moisten themselves. They may live entirely in water, or will come onto land even when there is enough oxygen in the water. Their eyes are high on the head, protruding and able to revolve independently, and have a movable lower lid. The eyes are retracted periodically into small cups below the head to moisten them. Such eyes are very effective as a means to watch for potential enemies on land but their vision under water is blurred. Mudskippers have elaborate reproductive behaviour which involves tail standing, flip-flops, and fin displays. They are very territorial and defend their territory against other mudskippers and crabs. They can deliver a skin-breaking bite to humans even though they are only about 15 cm long!

Genus Anatirostrum
Iljin, 1930

This genus comprises only a single species and so its characters are those of the species. The snout is very distinctive and details of neuromasts are not given here as they are not needed in identification, although of importance in relating the genus. The genus is closely related to the tadpole goby clade comprising Benthophiloides-Caspiosoma-Benthophilus and details are give in Miller in Miller (2004). This author also gives an alternative terminology for the arrangement of neuromasts than that of Ahnelt et al. (2000).

Anatirostrum profundorum
(Berg, 1927)

Dorsal view

Common names

gavmahi nuk-ordaki (= duckbill goby), gavmahi-ye poozehderaz.

[duckbill tadpole goby].

Systematics

This species was originally described in the genus Benthophilus Eichwald, 1831 by Berg (1927) but later Iljin (1930) erected a new genus because of its unusual and distinctive morphology. The type locality is the Caspian Sea at 37°58'N, 52°22'E at a depth of 294 m (but see below).

There are 14 fish under ZISP 23134 recognised as syntypes in Ahnelt et al. (2000) although Berg (1927) mentions 15 fish in his description. Ragimov (1985) states that Berg described this species from a single young specimen and also visually observed 15 others for a total of 16 in the type series.

Key characters

The duckbill tadpole goby is characterised by the elongate and flattened head which is similar to a duck's bill. Unlike gobies of the genus Benthophilus the body has minute platelets and granules, there are 8 rather than 6, vertical, suborbital series of pit organs, no postorbital occipital series, and no chin barbel or cheek flaps behind the jaw angle (Ahnelt et al., 2000).

Morphology

First dorsal fin with 3-4 spines, usually 4, second dorsal fin with 1 spine followed by 8-11, usually 10, soft rays. Anal fin with 1 spine followed by 8-11 soft rays. Pectoral fin rays 14-16. Gill rakers on the posterior part of the arch are very short and anteriorly are minute. Pit organs on the side of the head are papilliform and clearly visible with the naked eye. Further details of anatomy are given by Ahnelt et al. (2000).

Iranian specimens had the following meristics:- first dorsal fin with 4(4) spines; second dorsal fin with 1(4) spine followed by 10(4) soft rays; pectoral fin rays 14(1), 15(2) or 16(1); anal fin with 1(4) spine followed by 11(4) soft rays; and total vertebrae 29(4).

Sexual dimorphism

Females may retain dermal granules when mature.

Colour

Overall, colour is a light grey or pale fawn fading to a whitish grey on the belly. Various speckles and melanophores are found on the back and upper flank. The dorsal, caudal and pectoral fins have dark grey speckles. The head sides from the snout to the cheek are dark with transversal suborbital papillae series whitish giving the impression of narrow light stripes below the eye and on the cheek. The peritoneum is black or densely covered in fine speckles.

Size

Reaches 11.2 cm, or 13 cm total length (Jolodar and Abdoli, 2004). Females may be larger than males (mean total length 84 mm versus 77 mm).

Distribution

Found in the southern Caspian Sea including Iranian waters (Berg, 1927; Ahnelt et al., 2000; Abdoli and Naderi, 2009).

Zoogeography

Known only from the Caspian Sea and one of the endemic Sarmatian fauna (see Family Account).

Habitat

Found to a depth of 294 m on white silt bottoms according to Berg (1927) but the data in ZISP states 244 sazhems (= 446.5 m). Recent Iranian material is from 45-80 m, at 9.7-16.4°C at 50 m (Ahnelt et al., 2000) and Jolodar and Abdoli (2004) state it lives mainly at 50-100 m depths in the south Caspian Sea.

Age and growth

Unknown.

Food

Unknown but the duck bill may be an adaptation for feeding on silt bottoms (Ragimov, 1986).

Reproduction

Apparently mature eggs reach 1.9 mm in diameter in the Iranian specimen.

Parasites and predators

Unknown.

Economic importance

This species is too rare to be of any economic importance.

Conservation

Conservation requirements are unknown. Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria.

Further work

More specimens need to be caught to assess its distribution, numbers, variation and biology.

Sources

Type material: See above (ZISP 23134).

Iranian material: CMNFI 1999-0023, 4, 76.1-79.1 mm standard length, Gilan, Caspian Sea off Astara (38º00'N, 49º30'E to 38º20'N, 50º00'E).

Genus Babka
Iljin, 1927

Babka gymnotrachelus
(Kessler, 1857)

Caspian Sea basin but no Iranian record although Kottelat and Freyhof (2007) map it from the Iranian shore. Gobius macropus De Filippi, 1863 described from Lake Palestrom near Poti, Georgia is a synonym.

Babka macrophthalma
(Kessler, 1877)  

Reported from the south Caspian Sea by Naseka and Bogutskaya but no confirmed specimen from Iran.

Genus Benthophiloides
Beling and Iljin, 1927

Benthophiloides brauneri
Beling and Iljin, 1927

Originally described from the lower Dnieper River between Kherson and Kakhovka and the south Bug River between Novaya Odessa and Nikolayev, Ukraine and also recorded from the Caspian Sea basin but no Iranian record. Ragimov (1998c) and Miller (2004) give recent descriptions. Pinchuk and Miller in Miller (2004) question the validity of the Caspian Sea record for this species.

Benthophiloides turcomanus
(Iljin, 1941)

Caspian Sea basin, described from off Chikishlar at 37°45.5'N, 53°47'E and southwest of Ulsky Bank at 38°05'N, 52°34'E, Turkmenistan, but no Iranian record. Known only from the two type specimens, now lost (Reshetnikov et al., 1997). Miller in Miler (2004) places this species in Benthophiloides; formerly it was in the genus Asra Iljin, 1941. Miller in Miler (2004) gives a general map that encompasses the southeastern Caspian Sea including Iranian waters but the only records are not in Iran.

Genus Benthophilus
Eichwald, 1831

Recheck Benthophilus illustrations in this account for source (correct species)

The tadpole gobies are found in the Black and Caspian seas where there are about 20 species, 16 endemic to the Caspian (Pinchuk and Miller in Miller, 2004; Boldyrev and Bogutskaya, 2007). The general Farsi name for fishes in this genus is گاو ماهي (gav mahi) or سگ ماهي (sag mahi), not repeated under each species description.

Members of this genus are characterised by the broad and flattened head, dorsal muscles not extending to the eyes, no sensory canals or pores, first dorsal fin with 2-4 rays, well-separated form the second dorsal fin, the caudal fin has only 2 rows of papillae, head and body scaleless but with spinulose bony granules, scutes and platelets except in adult males which are naked (and cannot therefore be readily identified), anterior nostrils developed as small tubes overlying the upper lip, no swimbladder, a longitudinal dermal fold usually present on each side behind the mouth corner, and presence of a chin barbel. There is no pelagic larval stage and eggs are large and oligoplasmatic. Ahnelt (2003) discuss the unique specialisations in the postcranial skeleton of benthophiline gobies (which also includes Anatirostrum and Benthophiloides) including reductions in vertebral numbers and arrangement of pterygiophores. Pinchuk and Miller in Miller (2004) review other characters that show relationships of this specialised group within a larger tadpole-goby clade, the broad and flattened head being the most obvious.

Pinchuk and Miller in Miller (2004) give details of the head neuromast organs that characterise this genus, namely 6 transverse infraorbital rows, 1-4 before and 5s and 6s well above the level of the hyomandibular row b; row a is absent; row 5s is distant from row 4 which does not extend above the level of row b; rows 5i and 6i are arranged successively but row 5i is mostly below the level of row 6i separating the latter from the posterior end of row d; dorsal supraorbital rows o very short and well-separated in the dorsal midline; and supraorbital series p present in interorbit as 3 pairs of short transverse rows.

These fishes are found in brackish waters with a salinity up to about 20‰, in deeper waters, estuaries and coastal waters. They can dig themselves into bottom sediments and are usually found on mud, silt or sand. Food is insect larvae,  crustaceans and molluscs. Life span of these tadpole gobies is only a year, some individuals maturing at 6-7 months, called ephemery. Fish die after spawning, females earlier than males by 3-4 weeks (Boldyrev and Bogutskaya, 2004; 2007). Eggs are laid inside an empty mollusc shell.

Pinchuk and Miller in Miller (2004) and Boldyrev and Bogutskaya (2004; 2007) give descriptions and keys for all Caspian Sea species. The 5 species cited here are the ones with records from Iran although it is likely other species will eventually be found along the southern Caspian Sea coast.

Benthophilus abdurahmanovi
Ragimov, 1978

Endemic to the Caspian Sea, found in the North Caspian and reported from the south Caspian Sea by Naseka and Bogutskaya (2009). No Iranian record.

Benthophilus baeri
Kessler, 1877

Common names

gavmahi-ye Baer, gavmahi-ye tokmehsar.

[Ber comcaxulu in Azerbaijan; Baer pugolovka or Baer tadpole goby in Russian].

Systematics

Benthophilus Baeri was described from the Caspian Sea at Mangyshlak Peninsula, Kazakhstan and in the South Caspian.

A specimen listed as a syntype is in the Natural History Museum, London under BM(NH) 1897.7.5:16 (32.5 mm standard length) from St. Petersburg University (sic, ZISP?) with others in the Zoological Institute, St. Petersburg (ZISP 2239, lectotype and ZISP 53665 (ex 2239) (4)) and SPU 395 (463/410) (1) (Eschmeyer et al., 1996; Pinchuk et al., 2004).

Lectotype: ZISP 2239. Paralectotypes: (11) BMNH 1897.7.5.16 [ex St. Petersberg Univ.] (1), SPU 395 [463/410] (1), ZIN 53665 [ex 2239] (4).

Key characters

This species has very large and high, conical tubercles arranged in rows, not all tubercles are spinous, dorsal row tubercles usually 11-17 (lower than other Benthophilus), ventral row tubercles 9-14 (lower than other Benthophilus), granules are mostly absent between body tubercles rows, interorbit with a shallow median groove, a chin barbel is present, there are 1-2 dermal barbels behind jaw angle, the first dorsal fin has 1-2 spines, and dark bands are absent.

Morphology

First dorsal fin with 0-2 spines, usually 1 (Ragimov (1985) and Boldyrev and Bogutskaya (2007) but 2 according to Pinchuk et al. in Miller (2004)), second dorsal fin with 1 spine followed by 6-9, usually 7, soft rays. Anal fin with 1 spine followed by 5-9, usually 6-7, soft rays. Dorsal row tubercles 11-17, usually 13-15, lateral row 1-12, usually 7-9 (but sometimes completely absent), and abdominal row 9-14, usually 11-12. Total vertebrae 24-27. Tubercles on the head and flanks are large and can bear 1-4 sharp spines but only some tubercles retain spines. The dorsal tubercle row continues onto the head ending near the eyes while the lateral row is short, extending from a level between the dorsal fins and ending at the rear of the second dorsal fin. There may be a few small granules scattered between the major row tubercles and on the head. There is a long chin barbel, about equal to eye diameter. There is one neuromast in row 7 behind the eye.

A single Iranian specimen had ?

Sexual dimorphism

The second dorsal and anal fins of large males are enlarged.

Colour

The back, upper flank and upper head are pale grey to pale brown with dark grey speckles, and often minute dark dots form dark areas. Some bands may be weakly expressed on the back and flank, more obvious in immature specimens. The lower body and belly are whitish. The pectoral, second dorsal and caudal fins have dark grey speckles and bars while the other fins are pale.

Size

Reaches 8.6 cm for males and 6.9 cm for females.

Distribution

Found in the central and southern Caspian Sea, rarely in the northwest Caspian. Reported from Gorgan Bay, the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea in Iran (Kiabi et al., 1999; map in Reshetnikov, 2002; Pinchuk et al. in Miller, 2004; Abdoli and Naderi, 2009).

Zoogeography

A Caspian Sea endemic, part of a unique fauna poorly studied and collected in Iranian waters, as are all its relatives below.

Habitat

Found in depths of 5 to 81 m in littoral areas and also known to enter rivers in Russia (Reshetnikov et al., 1997). Found at 0.5-30.0 m in warm seasons and migrates to deeper water at 100 m in winter (Boldyrev and Bogutskaya ,2007). During the spawning season they are absent from shallow waters (5-10 m) and deeper waters (30-50 m)(Pinchuk et al. in Miller, 2004).

Age and growth

Up to 4 age groups are known (Reshetnikov, 2002) although Pinchuk et al. in Miller (2004) indicate life-span may be only 18 months.

Food

Corophiid crustaceans and some molluscs such as gastropods are principal diet items. Cumaceans, amphipods and Nereis worms are also important food items (Pinchuk et al. in Miller, 2004).

Reproduction

Mature males measure 8 cm while a mature female from the same collection was 6 cm (Berg, 1948-1949) while Pinchuk et al. in Miller (2004) state that both sexes are mature by 4.0 cm, in the first year of life. Eggs have a maximum diameter of 1.2-1.8 mm and a minimum diameter of 0.3-0.5 mm and fish up to 5.2 cm long produce up to 1860 eggs (Reshetnikov, 2002). Spawning takes place from the second half of May to August and rarely into September with a second batch of eggs laid in July (Pinchuk et al. in Miller, 2004). Eggs are laid on silt and silt-sand bottoms, probably using shells, at 10-25 m (Pinchuk et al. in Miller, 2004).

Parasites and predators

None recorded from Iran.

Economic importance

This species is food for sturgeon and Sander species (Pinchuk et al. in Miller, 2004).

Conservation

Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include possibly few in numbers, limited range (less than 25% of water bodies), absent in other water bodies in Iran, and absent outside the Caspian Sea basin.

Further work

The biology and distribution of this species in Iranian waters needs to be studied.

Sources

Type material: See above (BM(NH) 1897.7.5:16).

Iranian material:

Benthophilus casachicus
Ragimov, 1978

Endemic to the Caspian Sea and found on the eastern Caspian coast, the Volga delta area, and from the south Caspian Sea by Naseka and Bogutskaya (2009). No Iranian record.

Benthophilus ctenolepidus
Kessler, 1877

Common names

gavmahi-ye shafaf or shaffaf (= transparent or clear goby); gavmahi-ye Lankaran or gavmahi-ye Lenkoran.

[prozrachnaya pugolovka or transparent tadpole goby, shipogolovaya pugolovka or spiny-headed (?) tadpole goby in Russian; spiny-scaled tadpole goby; Lenkoranskaya pugolovka or Lenkoran tadpole goby in Russian for the subspecies in the southern Caspian Sea].

Systematics

A subspecies reported from off the Iranian coast was Benthophilus ctenolepidus pinchuki Ragimov, 1982 but this is now recognised as a distinct species by Pinchuk and Miller in Miller (2004) (see below). The lectotype of Benthophilus ctenolepidus as designated by Ragimov (1982) is in the Zoological Institute, St. Petersburg under ZISP 10897 with 3 paralectotypes lost and 1 paralectotype from ZISP in the Natural History Museum, London under BM(NH) 1897.7.5:13 (66.9 mm standard length) (Eschmeyer et al., 1996). The type locality is "yuzhnoi i srednei chastyakh' Kaspiiskago morya" (= southern and middle Caspian Sea), or Caspian Sea, 40°08'N, 0°26'E off Baku, Azerbaijan (in Eschmeyer's "Catalog of Fishes" online, downloaded 22 August 2007). Records of B. magistri Iljin, 1927 in the Caspian Sea, as B. m. lencoranicus Ragimov, 1982, are this species (Boldyrev and Bogutskaya, 2007). The taxon Benthophilus magistri lencoranicus Ragimov, 1982 was described from "raione protib Zelenogo bugra (38°10' s. sh.)" (= area opposite Green Hill, Turkmenistan). The holotype of lencoranicus is in the Caspian Biological Station, Institute of Zoology, Azerbaijan under CBSIZA 546 (no. 2), paratypes under 546 (20) and additional non-type material in the Zoological Institute, St. Petersburg under ZISP 23131 and 41912 (9) (Eschmeyer et al., 1996). Boldyrev and Bogutskaya (2007) were unable to locate IZA 546.

Key characters

The narrow head has a trough-shaped depression or groove on the occiput, the large tubercles are vertically elongate, curved and crest-like and have their rear edges fringed with a comb of spines, dorsal row tubercles usually 30-33, abdominal row tubercles usually 24-26, temporal and occipital region without large tubercles but having granules, the body has tiny granules anteriorly interspersed among the large tubercles, dermal filaments present or absent, a small but well-developed chin barbel is present, the dermal process behind jaw angle is lobed, narrow, with an acute protuberance, first dorsal fin spines 3-4 (rarely 2), and back without brown bands.

Morphology

First dorsal fin with 3-4 spines, second dorsal fin with 1 spine followed by 8-11, usually 9-10, soft rays. Anal fin with 1 spine followed by 7-11, usually 8, soft rays. Total vertebrae 29-230. Dorsal row tubercles 27-33, usually 30-33 (?) or 22-24 (Boldyrev and Bogutskaya, 2007), lateral row 11-22, usually 17-19, abdominal 20-26, usually 24-26 (22-24 in Boldyrev and Bogutskaya (2007)). Tubercles on the head (when present) and flanks are large and bear sharp spines, the flank tubercles being angular in shape. The dorsal row of tubercles is incomplete, usually beginning below the first dorsal fin. The first 3-4, and as many as 7, dorsal row tubercles are markedly smaller than the succeeding ones. The dermal plate or fold behind the mouth corner is large (1.2 times eye diameter), oval, and without a wavy margin.

Sexual dimorphism

Undocumented.

Colour

Mostly transparent as the name suggests, a light to ash grey. The body bears dark lines and speckles but no strong dark bands, spots or blotches. The belly is yellowish-white. The dorsal and pectoral fins have thin banding and the pelvic and and anal fins are pale.

Size

Reaches 10.7 cm.

Distribution

Found in the central, southwestern and southeastern Caspian Sea and in adjacent Iranian waters (Ragimov, 1965; Abdoli and Naderi, 2009). Records are from Astara on the Azerbaijan-Iran border to Hasan Kuli in Turkmenistan and adjacent waters.

Zoogeography

A Caspian Sea endemic.

Habitat

Found in depths of 0.5-74 m in littoral areas but deeper than B. magistri and B. macrocephalus. It feeds and spawns in 0.5-10.0 m and migrates to deeper water in winter. Occurs in higher salinity areas at 12.4-13.0‰. Jolodar and Abdoli (2004) place it at 30-200 m depths in the south Caspian Sea basin. The pelvic fin is less developed, shorter and not as dilated than in these shallow water species.

Age and growth

Life span is probably not more than 18 months with maturity at one year (Pinchuk and Miller in Miller, 2004).

Food

Food in northern Caspian specimens was found to include mostly corophiid amphipods, with some gammarids, other crustaceans, and gastropods (Pinchuk and Miller in Miller, 2004).

Reproduction

Spawning is thought to occur from spring to autumn and into winter (Pinchuk and Miller in Miller, 2004).

Parasites and predators

None reported from Iran.

Economic importance

None.

Conservation

Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include possibly few in numbers, limited range (less than 25% of water bodies), absent in other water bodies in Iran, and absent outside the Caspian Sea basin.

Further work

The biology and distribution of this species in Iranian waters needs to be studied.

Sources

Based on Pinchuk and Miller in Miller (2004).

Type material: See above under B. ctenolepidus (BM(NH) 1897.7.5:13).

Benthophilus granulosus
Kessler, 1877

Endemic to the Caspian Sea and found in coastal areas of the North and eastern and western Middle Caspian. No Iranian record although Kottelat and Freyhof (2007) map this species from the Iranian shore.

Benthophilus grimmi
Kessler, 1877

A Caspian Sea endemic found in the western part of the Middle Caspian and the northern part of the South Caspian south to about 39º40'N, and from the south Caspian Sea by Naseka and Bogutskaya (2009). No Iranian record.

Benthophilus kessleri
Berg, 1927

A Caspian Sea endemic found in coastal waters of the eastern Middle Caspian, and from the south Caspian Sea by Naseka and Bogutskaya (2009). No Iranian record.

Benthophilus leobergius
Berg, 1949

Common names

gavmahi-ye akhtari (= stellate or starry goby), gav mahi bacheh qurbaqei, gavmahi-ye bacheghoorbagheie, sebele.

[ulduzlu comcaxul or khazar julduzlu chomchakhulu in Azerbaijan; zvezdchataya pugolovka or stellate tadpole goby in Russian; Caspian starry goby, Caspian stellate goby].

Systematics

This taxon was originally described as a subspecies of Benthophilus stellatus (Sauvage, 1874). B. stellatus is now restricted to fish from the Black Sea. Note that views do conflict on the status of this taxon and more studies remain to be done (Pinchuk et al. in Miller, 2004).

The subspecies leobergius (sic; leobergi has been used, see below) was first proposed by Iljin (1949) and was thought not be available as no distinguishing features were given in the description (Eschmeyer et al., 1996) although Berg (1948-1949) gives a description referring to "higher development of spiny tubercles" and colouration "less bright" than then Black Sea form in his volume III dated 1949 (not 1948 as given in Eschmeyer et al. (1996)). Eschmeyer et al. (1996) consider that Berg may be the author of this taxon and Pinchuk et al. in Miller (2004) concur. The holotype is probably in the Zoological Institute, St. Petersburg under ZISP 10891 (Eschmeyer et al., 1996). Berg (1948-1949) notes that the taxon is found "in the freshened regions throughout the Caspian Sea, south to Astrabad Bay (No. 10891, 5 August 1874, 62 mm)". This may be the type locality, i.e. Gorgan (= Astrabad) Bay, Iran. However this specimen may be merely recording the southernmost distribution of the taxon and a larger fish at 103 mm under ZISP 23128 labeled as from the Caspian Sea could be the holotype as it is depicted in two views (Figure 858, p. 1115 in the Russian text and p. 196 in the English text, and Figure 859, p. 1116 Russian and p. 197 English). Both these fish may be syntypes. Iljin (1949) simply referred to "Kaspii", i.e. the Caspian Sea, as the type locality. Boldyrev and Bogutskaya (2007) selected ZISP 23128 as the lectotype.

Benthophilus macrocephalus variety b (large-scaled) Kessler, 1877 is a synonym of B. s. leobergius according to Berg (1948-1949). Benthophilus aculeatus Baer in Lukina, 1984 is possibly a synonym, with no types known (Boldyrev and Bogutskaya, 2007).

Kottelat (1997) considers, tentatively, that Benthophilus stellatus is restricted to the Black Sea basin. Furthermore, Kottelat points out that perhaps the Caspian Sea species is Benthophilus leobergi Ragimov, 1978, leobergi since the species is founded on a personal name and should be emended to this spelling and Ragimov, 1978 since the name is a nomen nudum in Iljin (1949) (no description or diagnostic characters (but see above)) until Ragimov (1978) makes the name available by listing characters distinguishing it from B. s. casachicus. Benthophilus casachicus Ragimov, 1978 is then another Caspian Sea species.

Key characters

Distinguished by stellate tubercles, mostly spinous at the tip, tubercles rows on body well-defined but scattered on head, dorsal tubercles 25-30, abdominal tubercles 21-25, granules present predorsally but mostly absent from head and body, interorbit without a median groove, chin barbel present but small (eye diameter or less), dermal process behind jaw angle obvious, 3-4 first dorsal fin spines, and first dorsal fin patterned. and dark bands present.

Morphology

The snout is very long, 30-33% of head length, and the upper jaw projects. The head is wider than long. There are 3-4 neuromasts in row 7 (also in B. macrocephalus, usually 1 in other species). First dorsal fin spines 2-6, usually 3-4, second dorsal fin with 1 spine and 6-11 soft rays, usually 8-10, anal fin with 1 spine and 7-9 soft rays. Pectoral fin rays 15-18. The gill arch is without evident rakers and is irregularly tuberculate. Vertebrae number 28-31. There are 10-11, often 11, precaudal vertebrae (commonly 9 in other Benthophilus). There is a flap behind the jaw angle. The gut is moderately long with several convolutions. The body bears 3 rows of very spinulose tubercles; the upper row numbering 25-30, usually 26-28 or 27-29 (authors vary), the lower 21-25, usually 23-25 or 22-24 (authors vary), and the dorso-lateral row 15-24, usually 18-20. The ventro-lateral row is usually absent.There are numerous small tubercles between the main rows on the flanks, particularly the dorsal and lateral rows. The head surface has numerous small and large tubercles, arranged irregularly. Small tubercles or granules are even found on the medial half of the eyeball. There are 2 well-developed tubercles on the midline between the eyes (in 80% of specimens) as opposed to one or none in other Benthophilus.

The chromosome number of B. leobergi is 2n=44 with 46-48 chromosomal arms (Grigoryan and Vasil'ev, 1993; Vasil'yev and Grigoryan, 1993) or 2n=46 (Klinkhardt et al., 1995).

Iranian specimens had the following meristics: first dorsal fin spines 3(1) or 5(1), second dorsal fin with 1 spine and 9 soft rays (2), anal fin with 1 spine and 8 soft rays (2), and pectoral fin with 17(2) branched rays. The extent of tubercle rows is difficult to distinguish since their size gradually decreases posteriorly and their arrangement is irregular anteriorly. Dorsal row tubercles 31(2), lateral row tubercles ca. 19(2), and lower row tubercles 23(1) or 24(1).

Sexual dimorphism

The pectoral fin is longer than the pelvic fins in males when spawning. Females have a very small chin barbel.

Colour

Overall colour is brownish to whitish-grey. The head surface and upper flank have large, dark brown spots and small dark speckles. The body has about 5 transverse bands which circle the first dorsal fin, rear of the second dorsal fin and caudal fin base when viewed from above. Rows of speckles are found on the second dorsal, pectoral and caudal fins.

Size

Reaches 10.7 cm.

Distribution

Found in the Caspian Sea. In Iran, it is reported from Gorgan Bay (Abdoli, 1994a). the Safid River (Abbasi et al., 1999), the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea (Kiabi et al., 1999; Abdoli and Naderi, 2009). Jolodar and Abdoli (2004) consider it to be widely distributed along the Iranian coast but more abundant in Gomishan Wetland and Gorgan Bay. It is also recorded between Kultuk and Astara in Azerbaijan, near the Iranian border (Ragimov, 1965).

Zoogeography

Endemic to the Caspian Sea.

Habitat

This species is found in the Caspian Sea and in brackish and fresh waters, and is widespread in coastal waters over sand and shell debris bottoms down to at least 100 m. Said to prefer salinities below 9‰. Feeding and spawning occur in shallow water at 0.5-10.0 m, retreating to deeper water in winter (Boldyrev and Bogutskaya, 2007). It is said not to enter fresh waters unlike its relative B. stellatus but is known from fresh water in the Volga delta. In spring and autumn it can be found in coastal zone at 1-20 m. It prefers warmer waters at 18-26ºC (Caspian Sea Biodiversity Database, www.caspianenvironment.org). e

Age and growth

Young fish reach 1.83 cm in January and early February after spawning in autumn and reach their maximum size in July-August of the following year at 8.5-9.4 cm and 21.6-24.7 g. The spring spawners reach 1.9-2.0 cm and 0.17-0.24 g in May-June and 3.5-5.9 cm and 1.1-5.4 g in July-August. With two spawning seasons, there are always fish of markedly different size and maturation stage in any population. Life span is about 18 months (Ragimov, 1985a). Abdoli et al. (2006) examined fish from the Gomishan and Miankaleh wetlands and found a length (L)-weight (W) relationship of W = 0.0499L^2.5 for males.

Food

Diet is dominated by molluscs (bivalves and gastropods) but includes crustaceans, worms, insect larvae and small fishes. An Iranian specimen contained the remains of a crab.

Reproduction

In the southern Caspian spawning occurs at depths of 30-35 m and in October-December and March-April (in the northern Caspian it is in shallow water (1-5 m) and during summer months). Batch spawning occurs and eggs number up to 2136 large and 1284 small with diameters 1.5-2.1 mm and 0.3-0.7 respectively (Ragimov, 1985a). Fecundity may reach 3500 eggs and maximum diameter 4.5 mm (Reshetnikov, 2002). Males protect the nests; unprotected nests have their eggs eaten by crustaceans within 2-3 hours (Caspian Sea Biodiversity Database, www.caspianenvironment.org).

Parasites and predators

Sattari et al. (2004) record the nematode Anisakis sp. from this species in Gilan. This fish is eaten by other fishes and by seals.

Economic importance

None.

Conservation

Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include medium numbers, medium range (25-75% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin.

Further work

The biology and distribution of this species in Iranian waters needs to be studied.

Sources

Iranian material: CMNFI 1971-0326A, mm standard length, (): CMNFI 1970-0543, (); 3, 90.4-90.9 mm standard length, Mazandaran, Gorgan Bay and the Caspian Sea.

Benthophilus leptocephalus
Kessler, 1877

A Caspian Sea, deep-water endemic found in the western Middle Caspian south to 39º41'N and the eastern South Caspian south to Hasan Kuli in Turkmenistan. No Iranian record.

Benthophilus leptorhynchus
Kessler, 1877

A Caspian Sea, deep-water endemic known from the western coast of the Middle Caspian and the north of the South Caspian south to Baku. No Iranian record.

Benthophilus macrocephalus
(Pallas, 1788)

Common names

gavmahi-ye vazaghi (= tadpole goby).

[iribas comcaxul in Azerbaijan; Kaspiiskaya pugolovka or Caspian tadpole goby in Russian; bighead goby].

Systematics

Eschmeyer et al. (1996) gave the publication date as 1788 (later 1787), Berg (1948-1948) and Pinchuk and Miller in Miller (2004) as 1787. The original description is dated 15. Mars. 1787 but was probably published in the following year (not verified). The type locality is the Caspian Sea near the mouths of rivers and streams, and in small inlets, although the type of Gobius macrocephalus was probably from the Volga delta. No type specimens are known.

Key characters

Distinguished by having moderate, stellate tubercles, spinous at their apex with usually 22-23 (but see below) in the dorsal row and 19-24 in the abdominal row, numerous granules over the head and body, head wide, width less than to slightly more than length, large snout tubercle, two rows of tubercles from dorsal rows extend onto temporal and occipital areas, no occipital groove, chin barbel present, dermal process behind jaw angle very large (base length 20-26% head length), rounded or scalloped in larger fish, first dorsal fin spines 3-4, no dark annular bands.

Morphology

There are 3-4 neuromasts in row 7 (shared with B. leobergius, usually one in other Benthophilus). The head is very wide , 103-111% head length (only B. leobergius has similar measurements). First dorsal fin with 2-4 spines, usually 3, second dorsal fin with 1-2 spines, usually 1, followed by 6-10 soft rays, mostly 8-9. Anal fin with 1 spine followed by 6-9, usually 7, soft rays. There are no evident gill rakers on the arch but rounded tubercles are present. Total vertebrae number 27-28, with 17-19 caudal vertebrae, usually 18. The head and body are covered with minute granules with larger stellate scutes or tubercles bearing sharp spines on the body and on the dorsal and lateral head surfaces. Granules extend onto the medial half of the eyeball and onto the pectoral fin base. Scutes are few and scattered on top of the head, strongly developed and close together on the side of the head. There are three longitudinal rows of tubercles on the body with 19-27, usually 22-23 (or 23-27, modally 25, authors differ) tubercles in the dorsal row, 8-16, usually 10-13, laterally, and 19-24 abdominally, usually 21-22. The ventro-lateral row is usually absent. The belly is naked. The gut is moderately elongate with several convolutions.

Iranian specimens had the following meristics: first dorsal fin spines 3(3), second dorsal fin with 1 spine and 8 soft rays (4), anal fin with 1 spine and 7 soft rays (4), and pectoral fin with 16(1) or 17(3) branched rays. The extent of tubercle rows is difficult to distinguish since their size gradually decreases posteriorly and their arrangement is irregular anteriorly. Dorsal row tubercles 25(4), lateral row tubercles 9(1), 13(2) or 14(1), and lower row tubercles 21(1), 22(2) or 23(1).

Sexual dimorphism

Mature males lose the granules, scutes and tubercles, their dorsal and anal fins enlarge and their cheeks become more muscular or inflated.

Colour

Overall colour is ash-grey with scattered melanophores on the upper flank and dorsal surface. Melanophores line the pectoral and caudal fin rays being best developed on the more dorsal rays.

Size

Reaches 13 cm.

Distribution

This species is reported from the Caspian Sea including the south from the Anzali Mordab and Gorgan Bay in Iran and between Kultuk and Astara in Azerbaijan (Ragimov, 1965).

Zoogeography

A Caspian Sea endemic.

Habitat

Found mostly in the sea over muddy bottoms but may approach river mouths. Commonly at 0.5-10.0 m, migrating to deeper areas at 20-25 m in winter. De Filipii (1865) reports this species from the Murdab (= Anzali Mordab presumably) in relatively fresh water.

Age and growth

Young fish taken in early June are 2.4-3.5 cm and 0.35-1.00 g and by the end of November they are 7.0-8.0 cm and 10.15 g, the maximum values for the species. By February-March they are nearly mature (Ragimov, 1985a). There are up to 4 age groups (Reshetnikov, 2002) although Pinchuk et al. in Miller (2004) suggest 18 months.

Food

Food includes molluscs (80%) crustaceans, fish, worms and chironomids (Zenkevitch, 1963). Iranian fish contained clams, crustaceans and a polychaete in gut contents.

Reproduction

Spawning takes place in April-May and rarely up to mid-June near the shore on silt or silt-sand bottoms with a mixture of shells. The eggs are laid in large, empty mollusc shells. Egg laying occurs in two batches as females carry eggs of two sizes. Fecundity of the larger eggs is up to 3180 and the smaller 1403. Their diameters are 2.0-3.0 mm and 0.3-0.6 mm respectively. Young are caught in early June (Ragimov, 1985a). Males probably die after spawning. An Iranian fish, 77.9 mm standard length, caught on 13 March had minute but developing eggs.

Parasites and predators

None reported from Iran.

Economic importance

None.

Conservation

Numbers in Iranian waters and threats to this species need to be assessed.

Further work

The biology and distribution of this species in Iranian waters needs to be studied.

Sources

Iranian material: CMNFI 1970-0543, CMNFI 1970-0544, mmm standard length, (); CMNFI 4, 55.3-82.8 mm standard length, Gilan, Caspian Sea near Bandar Anzali ().

Benthophilus mahmudbejovi
Ragimov, 1976

Endemic to the Caspian Sea and found on the western coasts of the Middle and South Caspian and the Volga delta region. No Iranian record.

Benthophilus pinchuki
Ragimov, 1982

Common names

None.

[Pugolovka Pinchuka or Pinchuk's tadpole goby in Russian]

Systematics

Originally described as a subspecies of B. ctenolepidus, Pinchuk and Miller in Miller (2004) recognise it provisionally as a distinct species. This taxon was described from "raione Belogo bugra y vostochnogo poberezh'ya Yuzhnogo Kaspiya" (= area of the White Hill (? locality not ascertained further by me) near the eastern coast of the southern Caspian Sea). A specimen listed as a syntype is in the Natural History Museum, London (no number, noted in October 1982). The holotype of pinchuki is in the Caspian Biological Station, Institute of Zoology, Baku, Azerbaijan under CBSIZA 52 (later in ZISP 53569, ex IZA), paratypes are under CBSIZA 304 (24, later 8 fish and ZISP 53660 9ex IZA 304) (6)). Additional material is in the Zoological Institute, St. Petersburg under ZISP 33143 (6) and 44346 (1) (Eschmeyer et al., 1996; on-line version downloaded 22 August 2007).

Key characters

Tubercles are vertically elongated, curved and crest-like, with a spiny fringe on their rear edge, dorsal row tubercles complete and 30-33, ventral row tubercles 23-27, granules are absent postorbitally on the head and on the body, temporal and occipital region without large tubercles, head narrow, the interorbit has a shallow median groove, dermal filaments present or absent, chin barbel usually present, dermal process behind jaw angle narrow (less than eye diameter) and barbel-like, first dorsal fin spines 3-4, and colour without dark bands.

Morphology

The first dorsal fin has 3-4 spines, usually 4, the second dorsal fin 1 spine and 9-11 soft rays, and the anal fin 1 spine and 8-11 soft rays (Ragimov, 1982; note the holotype has a much lower count of anal fin rays than figure in table). Dorsal row tubercles 30-33, usually 31-32 (other species having 30 or less usually except B. ragimovi), ventral row tubercles 23-27, and dorso-lateral row tubercles 10-23. Total vertebrae 30-32 and caudal vertebrae 21-23 (26-31 and and 17-21 in most other Benthophilus). The pelvic fin extends to the anus or beyond. Chin barbel less than half eye diameter. One neuromast in row 7.

Sexual dimorphism

Males may have longer pectoral fins than females and grow larger than females.

Colour

Not described except for the absence of dark bands, blotches and spots. Probably an overall greyish.

Size

Reaches 8.9 cm in males.

Distribution

Found throughout the Caspian Sea.

Zoogeography

Endemic to the Caspian Sea.

Habitat

Known down to 282-294 m, usually 50-100 m but as shallow as 20 m, and a salinity of 12.4-13.2‰.

Age and growth

Life span is probably 18 months with maturity at 1 year.

Food

Unknown.

Reproduction

Spawning probably occurs in spring as fry have been caught in late April.

Parasites and predators

Unknown.

Economic importance

None.

Conservation

Numbers in Iranian waters and threats to this species need to be assessed. Boldyrev and Bogutskaya (2007) call it a rare deepwater species.

Further work

The biology and distribution of this species in Iranian waters needs to be studied.

Sources

No specimens examined, based on Pinchuk and Miller in Miller (2004).

Benthophilus ragimovi
Boldyrev and Bogutskaya, 2004

Endemic to the Caspian Sea from the western coast of the Middle and South Caspian, south to Astara. No Iranian record.

Benthophilus spinosus
Kessler, 1877

Endemic to the Caspian Sea from the eastern and western coast of the Middle Caspian , the southeastern North Caspian and southeastern South Caspian. No Iranian record.

Benthophilus svetovidovi
Pinchuk and Ragimov, 1979

A Caspian Sea endemic found on the eastern coast of the Middle Caspian, and from the south Caspian Sea by Naseka and Bogutskaya (2009). No Iranian record.

Genus Boleophthalmus
Valenciennes, 1837

This genus of gobies comprises several species in the Indian Ocean including one reported from Iran.

The genus is characterised by a very elongate, compressed body, a rounded head, greatly thickened head and nape epidermis (as protection against drying when out of water), scales cycloid, moderate to minute in size, eyes high on the head and close together, lower eyelid or dermal cup well-developed, mouth slightly oblique, teeth in a single row in each jaw, upper jaw teeth conical with some canines, lower jaw teeth flattened, obliquely notched and almost horizontal, tongue truncate and nearly all adnate to mouth floor, gill opening small and oblique, and second dorsal and anal fins long (23 or more rays).

Boleophthalmus dussumieri
Valenciennes, 1837

Sarbaz River, courtesy of Asghar Mobaraki

Zirdan Dam, Kaju River, 26 December 2011, courtesy of Asghar Mobaraki

Zirdan Dam, Kaju River, 26 December 2011, courtesy of Asghar Mobaraki

Common names

gel-ye mahi cheshm navari (= band- or bar-eyed goby) or gavmahi-ye cheshmnavari.

[guloo in Pakistan; bar-eyed goby, tank goby, white goby, flathead goby, crocodile goby].

Systematics

Gobius giuris was originally described from the Ganges River, India.

Key characters

As the sole representative of the genus in Iran, the characters of the genus serve to identify it.

Morphology

The first dorsal fin has 6 spines, the second dorsal fin has 1 spine followed by 7-9 soft rays, the anal fin has 1 spine and 7-9 soft rays and the pectoral fin has 16-21 branched rays. Lateral series scales 28-36. Scales on the head are mostly cycloid while body scales are ctenoid. The exposed portion of flank scales are diamond-shaped. Scales are rectangular in overall shape with a rounded anterior margin which may be slightly indented above and below the mid-point, parallel dorsal and ventral margins, and a posterior margin with two straight edges meeting at a rounded central tip. The anterior dorsal and ventral corners are sharp. There are fine ctenii on the posterior margin. Numerous radii radiate anteriorly from the rounded central tip of the posterior margin. Circuli are fine. Esmaeili et al. (2009) give details of scale morphology using scanning electron microscopy. Gill rakers are short and reach the one below when appressed. The cheek has 3-5 longitudinal mucus canals. The gut is short and s-shaped.

The chromosome number is 2n=46, with 46 acrocentric chromosomes and 46 chromosomal arms (Subrahmanyam, 1969; Ráb, 1985; Vasil'ev and Grigoryan, 1993; Klinkhardt et al., 1995).

Meristics on Iranian specimens: first dorsal fin with 6(3) spines, second dorsal fin soft rays 9(3), anal fin soft rays 8(3), and pectoral fin rays 19(1) or 20(2). Scales in lateral series 32(1) or 36(1), total gill rakers 12(1) or 14(1) and total vertebrae 27(1).

Sexual dimorphism

Males are larger than females. Male dorsal fins are longer and their overall colour is brighter (Pethiyagoda, 1991).

Colour

Olive-green to blackish-green or yellowish to sandy brown on the back with flanks similar but lighter, often a greenish-yellow. The belly is cream coloured. The head and body are darkly blotched and spotted. The flank may have 5 regularly spaced blotches. The sides of the head have irregular dark to violet spots. The fins have thin bars appearing as rows of spots on each fin ray, in some concentrated at the base of the second spine of the first dorsal fin. Fins are a yellowish-green. The first dorsal fin may have a dark spot posteriorly and the anal fin a black margin. The pectoral fin has a dark spot above the base. Small preserved fish are immaculate. The peritoneum is silvery with a few small and scattered melanophores.

Size

Attains about 50 cm.

Distribution

Found in the Indo-West Pacific entering rivers. Abdoli (2000) maps this species as questionably present in the lower Karun and Arvand rivers of the Tigris River basin, questionably in the Gulf and Hormuz basins; and in lower reaches of Makran rivers from the Jagin to the Bahu Kalat or Sarbaz. It is recorded from the Hormuz and Makran basins by specimens.

Zoogeography

The marine abilities of some members of this family would aid in dispersal between river systems connected to the sea.

Habitat

Sand and mud substrates are preferred over rock in Sri Lanka (Pethiyagoda, 1991). The fish lies embedded in the sand with only the eyes protruding and rarely swim freely. Young fish may form schools or may rest close to shore in shallow water where they can be caught by hand. Tekrival and Rao (1999) report its aquarium preferences and habits as 22-25°C, pH 6.5-7.2, predator, almost dark lighting, bottom dwelling with stones preferred and a pair or more can be kept. Asghar Mobaraki (pers. comm., 8 January 2012) recorded a fish kill of this species on 26 December 2011 at the Zirdan Dam construction site on the Kaju River.

Age and Growth

Hossain et al. (2009) found a value close to isometric for this fish in the Ganges River of northwestern Bangladesh (b = 3.068 for total length and combined sexes, 2.954 for males and 3.293 for females)

Food

Diet includes small fishes seized from its concealment in the sand by a sudden lunge; this species being a visual ambush predator. It may browse on the substrate and take living food. An Iranian specimen had crustacean remains.

Reproduction

Eggs are green and when laid become strongly attached to any submerged structure by a tube 3-8 mm long. The eggs are 0.5 mm in diameter. Freshwater populations may migrate to the sea to breed as there is a marine larval stage although some are reported to be land-locked in South Asia and hence freshwater breeders (Pethiyagoda, 1991). The spawning period is June to September, peaking in July to August (Saksena, 1980).

Parasites and predators

None reported from Iran.

Economic importance

This goby is a food fish in South Asia and can be caught on light angling gear. It has been reported as being ciguatoxic (intermittently poisonous through feeding on toxic food) (Bagnis et al., 1970).

Conservation

The distribution and abundance of this species in Iranian waters has not been examined and no conservation assessment can be made.

Further work

This species seems to have a fairly restricted distribution in Iran and this should be investigated further.

Sources

Iranian material: CMNFI 1979-0322, 2, 20.7-53.6 mm standard length, Baluchestan, Sarbaz River (ca. 25º45'N, ca. 61º26'E); OSU 8124, 1, 162.0 mm standard length, Baluchestan, Bahu Kalat, Sarbaz River (25º43'N, 61º25'E).

Genus Hyrcanogobius
Iljin, 1928

Hyrcanogobius bergi
Iljin, 1928

This species was described from the north Caspian Sea near the mouths of the rivers Volga, Ural and Emba. Ragimov (1977) reports this species from off Gasan Kuli at 37°30'N in Turkmenistan near Iranian waters. Shakirova and Sukhanova (1994) record this species from the Atrek lakes of Turkmenistan, the Atrek River flowing into Iran for part of its course. Gobius longecaudatus var. c Kessler, 1877 described from Baku Bay is a synonym. Miller and Pinchuk in Miller (2004) map this species from Iranian waters (Gorgan Bay) but this is not confirmed by specimens. Miller and Pinchuk in Miller (2004) give a recent description of this species.

Genus Knipowitschia
Iljin, 1927

This genus of sand gobies has about 16 species in the Caspian, Black, Aegean and Adriatic seas and adjacent fresh waters with 2 recorded from Iran. Later spelt Knipovitschia, incorrectly, in the English summary of Iljin's 1928 description. The original description is apparently in Iljin (1927d) (as is that of Caspiosoma) but was repeated in Iljin (1928). Hyrcanogobius Iljin, 1928 and Bubyr Iljin, 1930 are synonyms (Economidis and Miller, 1990) although Miller in Miller (2004) separates Hyrcanogobius.

The body is fusiform without a strongly depressed head, the dorsal profile anteriorly being straight. The mouth angle does not reach past the anterior part of the eye. The mouth is oblique. The eyes are moderate in size and may be lateral or directed upwards. The body usually bears imbricate ctenoid scales but the head is naked as can be the anterior part of the back as far as the second dorsal fin and the middle of the abdomen to the anal fin. There may be axillary scales and scales on the belly midline. Some members lack scales except for the axillary region and the caudal peduncle. Lateral series scales less than 40. There are no barbels and the anterior nostrils are not an extended tube-like structure. The posterior nostrils are pore-like. The nape lacks a bony crown and only the posterior part of the cranium is covered with dorsal muscles. The preoperculum lacks teeth or projections. The isthmus is broad and the branchiostegal membrane is attached to its entire lateral margin. Jaw teeth are conical, caniniform and in several rows forming a band. The outer row is slightly enlarged but there are no strongly enlarged teeth. The vomer lacks teeth. The tongue is truncated or slightly rounded. The gill rakers are small and broadly spaced apart. The pectoral fins lack fine, silk-like rays. The anterior edge of the pectoral girdle lacks dermal flaps. The pelvic fin disc reaches to, or near to, the anus. The pelvic fin anterior membrane is well-developed but without obvious lateral lobes. The caudal peduncle is slender and longer than the second dorsal fin base. The upper angle of the caudal fin is nearly rectangular and the caudal fin is rounded and shorter than the head. The head canals are variably developed or absent, and may be damaged by abrasion in poorly preserved material. The first dorsal fin modally has 6 or 7 rays and vertebral modes are 30-33. The swimbladder is present or reduced. There is no perianal organ. Colour is light. Postlarvae are planktonic.

Miller in Miller (2004) also defines this genus by characters of the head lateral line system, namely having the infraorbital longitudinal row a present with typically at least 2 transverse rows from this row; transverse infraorbital rows between levels of rows b and d along cheek, with rearmost descending behind posterior end of row d; transverse row behind jaw angle not descending below level of row d; row b short, to below rear eye; anterior row tra distant from row b; anterior dorsal row g distant from row n; snout rows r and s linear; uniserial row of papillae along upper edge of each orbit when canals are absent but never with transverse rows; anterior oculoscapular canal (if present) ending anteriorly in interorbit, dividing from pore κ to end at double pores β; posterior oculoscapular present or absent; and preopercular canal when present always lacks middl;e pore δ.

Vasil'eva and Kuga (2001) propose that the separation of Knipowitschia from Pomatoschistus is doubtful based on similar cranial osteology and the variation in the degree of development of head canals seen in Knipowitschia. However Miller in Miller (2004) disagrees and presents arguments for a "sand-goby" group of 5 distinct genera, of which only Knipowitschia and Hyrcanogbius are known from Iran (Pomatoschistus, Gobiusculus and Economidichthys being the others).

Miller (1990) states that the majority of the members of this genus evolved after the draining of the Western Paratethys basin into the Adriatic Sea basin in the late Miocene about 6.0-5.5MYA.

.Members of this genus are called gav mahi and سگ ماهي (sag mahi) in Farsi and this not repeated under each Species Account.

Knipowitschia caucasica
(Berg, 1916)

Common names

gel-ye mahi qafqazi (= Caucasian goby) or gavmahi-ye qafqazi.

[gafgaz xulu in Azerbaijan; bubyr kavkazskii in Russian; Caucasus bald goby; Caucasian dwarf goby].

Systematics

Pomatoschistus caucasicus was originally described from Batumi/Temirgoe, a station south of the Sulak mouth on the Black Sea.

The name of this species first appeared in Kavraiskii in Radde (1899) as a museum name without a description ( a nomen nudum) and was subsequently made available by L. S. Berg in 1916 with the type locality being a swamp near Batum and Lake Inkit near Pitzunda, Georgia (see Eschmeyer (1990) and Eschmeyer et al. (1996) for details).

Gobius lenkoranicus Kessler, 1877 described from "pribrezhnom' bolote, po blizosti Lenkorana" (= a coastal marsh near Lenkoran, Azerbaijan) is a synonym, tentatively so according to Economidis and Miller (1990). This name was suppressed by the International Commission on Zoological Nomenclature (see Kottelat, 1997; Miller et al. in Miller, 2004)). This earlier name for what could be caucasica was suppressed as a nomen dubium because of an inadequate original description in its details and the small and poorly-preserved holotype which could not be readily compared with caucasica. The name could also have been suppressed as a nomen oblitum as it had not been used for 50 years (Economidis and Miller, 1990).

Formerly placed in the genus Pomatoschistus Gill, 1863 and in the genus Bubyr Iljin, 1930.

Three syntypes from Lake Temirgorje, Georgia (formerly in the Tiflis Museum) are in the Natural History Museum, London under BM(NH) 1896.3.28:26-28 (22.1-25.2 mm standard length) (Eschmeyer et al., 1996; personal observations). Economidis and Miller (1990) list these three specimens (as evidenced by the catalogue numbers 26-28) as two males (22.8-24.0 mm standard length) and two females but give the length of only one female (24.5 mm). Miller et al. in Miller (2004) consider the material used by L. S. Berg (see above) to be the type series (ZISP 15343 from Lake Inkit and ZISP 15321 a swamp near Batum).

Key characters

The anterior oculoscapular lateral line head canals unite in the posterior interorbit, with a single median pore κ, and canals extend anteriorly to pores λ. The preopercular canal is present (Miller in Miller, 2004).

Morphology

First dorsal fin with 5-8, usually 6, spines (rarely 4 as an anomaly, e.g. in Berg (1948-1949, Fig. 784 (Iljin, 1956)), second dorsal fin with 1 spine and 6-10 branched rays, usually 7-8, anal fin with 1 spine and 5-10 branched rays, usually 7-8, and pectoral fin with 13-18 rays. Lateral scales 29-38. Vertebrae 30-33. The back in front of the first dorsal fin and the belly in front of the anal fin are usually scaleless. The caudal peduncle is completely scaled and there is a complete row of scales anteriorly along the lateral midline, although other flank scales may be missing. The anterior oculoscapular head lateral line canals join in the posterior interorbit region, with one pore κ, and paired canals in the interorbit each to a pore λ and single pore α. The posterior oculoscapular canal is typically present, the preopercular canal is present and there are no additional pores on the horizontal anterior oculoscapular canal behind the eyes (Miller et al. in Miller, 2004). The subopercular canal is variably present which has led to different generic assignments for this species. The larva has been described by Daoulas et al. (1993).

Meristic values for Iranian specimens are:- first dorsal fin spines 6(4), second dorsal fin rays after a spine 6(1) or 8(3), anal fin rays after a spine 8(2) or 9(2), lateral scales 33(1), 34(1), 36(1), 39(1), and total gill rakers 9(3) or 10(1). Rakers are very short, not reaching half way to the adjacent one when appressed.

Sexual dimorphism

See under colour. Males are larger than females. There are various morphometric differences (Miller et al. in Miller, 2004).

Colour

Overall colour is grey to fawn with olive-green tints. Fish in hypersaline habitats are darker. Males are generally darker than females and have distinct dark bars on the flanks below the two dorsal fins and on the caudal peduncle while females have irregular spots or blotches along the flank mid-line. Nuptial males have 4 prominent bars. However some males may lack bars and have spots and some females lack spots (Ahnelt et al., 1995). The head in males is densely pigmented, including ventrally. The caudal peduncle is completely pigmented, usually including the ventral surface. The flank bar under the first dorsal fin in males is long and usually runs from near the dorsal mid-line to the belly. The male first dorsal fin has three oblique dark bands and a dark spot medially on rays 5 and 6 extending posteriorly on the fin membrane. The distal edge of this dorsal fin is dark. The second dorsal fin has three bands also and a dark edge. Males have dark pigment on the pelvic fins, head and breast, and a silver hue on the anal fin during the breeding season. The male pectoral fin has a short and oblique dark band on the upper rays. The anal fin in males is normally dark with a pale margin while in females it is pale overall. The caudal fin has thin dark bands.

Females are a pale fawn overall. The female has a densely spotted first dorsal fin while the male has a blue blotch at the fin rear when in breeding condition. The first dorsal fin in females has a distinctive middle band but the others are faint. The second dorsal fin in females is only faintly banded. Breeding females have 2 intensely black areas on the first dorsal fin, a black spot on the lower jaw, 2 rows of melanophores running obliquely from the eyes to the upper jaw, and a yellow abdominal region (Economou et al., 1994). The back has fine melanophores extending to the rear of the second dorsal fin. There are light saddles at the origins of the first and second dorsal fins, the end of the second dorsal fin and on the caudal peduncle. The mid-flank has several blotches, some slightly deeper than wide. The rest of the body below these blotches is pale except for some short vertical groups of melanophores below the lateral midline and melanophores along the base of the anal fin. The breast is pale as opposed to dark in males.

Large and minute pigment blotches and spots variably developed are scattered over the whole head and body in both sexes of an Iranian sample. The peritoneum has large pigment spots ventrally or is almost immaculate.

Size

Reaches 48.6 mm, perhaps 69 mm, total length. Fish in Gorgan Bay reached 46.0 mm (Afraei and Hassannia, 1999).

Distribution

Found in the Aegean, Black and Caspian Sea basins. Introduced to the Aral Sea. Caspian localities include Imeni Kirova or Kyzylagach Bay near the northwestern Iranian border, the lower Safid River and lower Babol River, near Anzali and Ashuradeh (Derzhavin, 1934). It is reported from Gorgan Bay, the delta of the Karasu, the Atrak River, the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea (Kiabi et al., 1999; Jolodar and Abdoli, 2004; Miller et al. in Miller, 2004; Abdoli and Naderi, 2009).

Zoogeography

This species is part of  marine fauna in the eastern Mediterranean and the Black-Caspian-Aral seas basins and its relationships are outlined under the genus description above.

Habitat

This species lives and reproduces in salinities as high as 59.5‰ and up to 83‰ (Zenkevitch, 1963; Miller et al. in Miller, 2004) but also enters fresh water. Preferred conditions in the Aegean area are 15-20‰ (Ahnelt et al., 1995; Miller et al. in Miller, 2004). Juveniles prefer sand, mud or gravel bottoms near shore in Greece (Daoulas et al., 1993) but weedy shallows are also favoured (Economidis and Miller, 1990). They may overwinter in deeper water at 1-2 m in the Volga delta (Economidis and Miller, 1990) and migrate into shallow water in April-May prior to spawning (Miller et al. in Miller, 2004). The Atrek River population moves downstream (Miller et al. in Miller, 2004). Afraei et al. (2001) found this species to be most frequent in Gorgan Bay in January and least frequent in March.

Age and growth

Life span may be only 1 year and as a consequence numbers can fluctuate widely in any given year depending on environmental conditions. In the Evros Delta of the north Aegean Sea, fish grow rapidly during the summer after hatching, breed from the end of April to the end of July in the following summer and grow rapidly again from July to September. Older males die the following year after February but some females will survive to spawn a second time at the end of April and the beginning of May and then die. Fish may be mature at 14.5 mm total length (Kevrekedis et al., 1990). In the spawning season, females comprise as much as 85.5% of the population (Miller et al. in Miller, 2004).

A study of this species in Gorgan Bay, Golestan (Iranian Fisheries Research Organization Newsletter, 23:2, 2000) showed that the maximum size obtained was 46 mm with average lengths of 33 and 37 mm for males and females respectively. The sex ratio was 1:1.1 for males to females and growth is positive allometric (see also Afraei and Hassannia (1999) and Afraei et al. (2001)). In the Volga delta spawning males were 33.3 mm and females 30.2 mm on average (Miller et al. in Miller, 2004). Abdoli et al. (2006) examined fish from the Gomishan and Miankaleh wetlands and found a length (L)-weight (W) relationship of W = 0.135L^2.72 for males, 0.0377L^1.97 for females and 0.0182L^2.51 for sexes combined.

Food

Diet was dominated by polychaete worms and chironomids (88%) in one study but crustaceans such as amphipods, copepods, ostracods, cladocerans, insects such as choronomids, bivalve mollusc larvae, and fish are also taken and items may be both benthic and planktonic.

Reproduction

Females may be carrying eggs at 20-24 mm and 8-10 months of age. Fecundity reaches 1389 eggs but can be as low as 60 eggs. Fecundity in the Caspian Sea ranges from 209 to 786 eggs with a mean of 423, from 209 to 382, mean 285 and from 527 to 863, mean 715.6 for various reports (Kevrekedis et al., 1990). Batches consist of 80-100 eggs. Eggs are cylindrical, 2.6 x 0.97 mm. Larvae are pelagic and as small as 4.1 mm standard length. Relative fecundity in the Gorgan Bay study in Iran was 290-550, mean 395.5 eggs (Afraei et al., 2001).

There is a pre-spawning migration into shallow water in April in the Caspian Sea. The male approaches the female from below, touching her lower jaw with his snout and leading her to a reed nest. Such behaviour occupies several hours to more than a day. The female enters the reed nest, inverts and deposits eggs on the roof of the nest. The underside of bivalve shells or gravel may also be used. The male then fertilises the eggs, inverting to do so. The eggs are laid in a line and the pair will form other lines. Egg patches may eventually contain as many as 3000 eggs at different developmental stages, which indicates males may spawn with several females. Spawning takes about 1.5 hours and the female gradually loses the brightness to her breeding colours and almost all breeding pigment is lost within a day. The pair mated 4 times over a period of 35 days (28 March, 6 April, 14 April and 2 May in an aquarium with fish from Lake Trichonis, Greece). The male remains mostly inside the reed nest, aerating the eggs and defending them against other gobies. At irregular intervals (8-60 minutes), the male would leave the nest for 1-5 minutes, occasionally feeding but always remaining near the nest.

Spawning in the pre-estuary area of the Volga River in the Caspian Sea takes place from the middle of April to the end of May, rarely to June. Spawning in the Caspian takes place in shallow water with some current at a depth of 0.15 to 1.5 m, a temperature of 15-27°C and over a wide range of salinities (Kevrekedis et al., 1990).

Parasites and predators

None reported for Iran.

Economic importance

None.

Conservation

This species seems to be rare in Iran with only Derzhavin's (1934) report and one other record. Its status cannot be assessed until more is known about its distribution. Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include abundant in numbers, habitat destruction, limited range (less than 25% of water bodies), absent in other water bodies in Iran, absent outside the Caspian Sea basin (sic).  Vulnerable in Turkey (Fricke et al., 2007).

Further work

Further collecting will need to be carried out to determine its abundance and distribution in Iranian waters. Its small size may have led to it being ignored or confused with other gobies as young and it may be more widely distributed than current knowledge indicates.

Sources

Iranian material: Uncatalogued, 4, 22.2-35.3 mm standard length, Mazandaran, Gorgan Bay (no other locality data).

Knipowitschia iljini
Berg, 1931

Common names

gavmahi-ye Iljin, gel-ye mahi.

[Iljin's bychok in Russian, Iljin xulu in Azerbaijan].

Systematics

At least 4 syntypes are in the Zoological Institute, St. Petersburg (ZISP 22052) along with ZISP 24370 and possibly ZISP 24424 (Miller and Pinchuk in Miller, 2004). Although Berg (1931b) states "many specimens caught" this may refer to abundance while only 4 fish are illustrated and may be the type series. This species was described from "in the middle part of the Caspian Sea".

Key characters

The anterior oculoscapular lateral line head canals are more or less separate in the midline of the posterior interorbit, with double or separate pores κ, and canals extend anteriorly through interorbit of variable extent. The preopercular canal is absent or present (Miller in Miller, 2004).

Morphology

The first dorsal fin has 6-8 spines, usually 7, the second dorsal fin has 1 spine followed by 8-10 soft rays, the anal fin has 1 spine and 7-10, usually 9, soft rays, the pectoral fin has 15-18 rays. Lateral series scales 28-38. Vertebrae 31-33. Scales are ctenoid. The belly, head and the dorsal surface back to the second dorsal fin are all naked. There is no small, straight canal extending posteriorly from the junction of the orbital canals. The caudal fin is rounded and symmetrical. The anterior oculoscapular lateral line head canals do not unite in the posterior interorbit. Canals anterior to pores κ are typically absent and pore κ is double. The posterior oculoscapular canal is absent, the preopercular canal absent or present. Pore "a" is single or double with sometimes an additional pore or two on horizontal anterior oculoscapular canal behind eye.

Sexual dimorphism

Males have darker overall colouration and darker fins than the females (see below). The first dorsal fin in males has free tips and usually a dark spot at the rear margin. Males have a pointed genital papilla while females have a distally bifurcated papilla. The pelvic fins reach the genital papilla in males while in females they do not reach the vent. Females have a more slender caudal peduncle and the snout is more produced than in males.

Colour

The body overall has a brownish reticulate pattern. The back and flanks bear about 6-10 dark bands in males while in females bands are faint and restricted to the posterior flank. The male has a darkly edged caudal fin and the pectoral fin is dark ventrally. The dorsal fins have dark stripes and the anal fin has a dark stripe along its margin in males while females lack stripes. Females bear small dark spots irregularly distributed on the back and anterior flanks.

Size

Attains about 4.7 cm for males and 5.0 cm for females. Ragimov (2003) gives a maximum length of 5.2 cm.

Distribution

Ragimov (1965) reports this species between Kultuk and Astara in Azerbaijan and generally in the central and southern Caspian Sea, and mapped around the coast of the whole Caspian by Miller and Pinchuk in Miller (2004).

Zoogeography

This species is part of a marine fauna in the eastern Mediterranean and the Black-Caspian-Aral seas basins and its relationships are outlined under the genus description above.

Habitat

Found benthically and in the water column with adults in shallow coastal areas at 20-70 m with juveniles offshore as deep as 500 m Not recorded from fresh water.

Age and growth

Life span is estimated at one year (Miller and Pinchuk in Miller, 2004).

Food

Only mysids have been recorded from 8 fish examined (Miller and Pinchuk in Miller, 2004).

Reproduction

Gonad maturity begins in late August to early September, many fish are ripe by the end of January and most by the end of February. Spawning occurs from early April to possibly as late as September with a peak in May-June (Miller and Pinchuk in Miller, 2004). Fecundity reaches 2240 eggs and egg diameter 0.8 mm (Miller and Pinchuk in Miller, 2004).

Parasites and predators

None reported from Iran but sturgeon and Sander species eat this fish (Miller and Pinchuk in Miller, 2004).

Economic importance

None.

Conservation

Apparently rare in Iran but this may reflect collecting effort for this small species. Insufficient work has been devoted to this species to assess its status.

Further work

Further collecting will need to be carried out to determine its abundance and distribution in Iranian waters. Its small size may have led to it being ignored or confused with other gobies as young and it may be more widely distributed than current knowledge indicates.

Sources

Iranian material: None.

Knipowitschia longecaudata
(Kessler, 1877)

Black and Caspian seas, described from the southern and middle Caspian Sea, but no Iranian record. Ragimov (1965) reports this species between Kultuk and Astara in Azerbaijan. Sometimes spelt longicaudata erroneously in the literature.

Genus Mesogobius
Bleeker, 1874

This is an endemic Ponto-Caspian genus with 2-3 species, with one species being of uncertain status (see below). It is distinguished by having three (rather than the more usual two) transverse head papillae rows between rows b and d. Other characters include suborbital papillae in transverse rows, no row a, snout with longitudinal rows s¹ and s², no perianal organ; row 5i not below level of row 6i, 6i at or opposite end of row d, scales normal, anterior nostril elongate but not overhanging lip, and pelvic fins without lobules. A detailed, recent description is given by Miller in Miller (2004).

Mesogobius nigronotatus
(Kessler, 1877)

Caspian Sea basin, described from Fort Aleksandrov (= Shevchenko) on the Caspian Sea coast of Kazakhstan, and from the south Caspian Sea by Naseka and Bogutskaya (2009), but no Iranian record. The only specimen was lost (Reshetnikov et al., 1997). M. nonultimus may be a synonym (Pinchuk and Miller in Miller, 2004).

Mesogobius nonultimus
(Iljin, 1936)

Common names

[bychok neposledniy or seriy bychok-martovic in Russian; Caspian toad goby]

Systematics

Described from 24 miles southwest of Ulsky Bank, Caspian Sea, Turkmenistan. The type is lost. May be a subspecies of Mesogobius batrachocephalus (Pallas, 1814) although Miller revises his opinion in Pinchuk and Miller in Miller (2004) and recognises it as a distinct species. See also under M. nigronotatus above.

Key characters

It is distinguished by having three (rather than the more usual two) transverse head papillae rows between rows b and d. Nape scales weakly ctenoid, almost reaching median pore κ, snout less than twice eye diameter, lower jaw not protruding, and males with distinct breeding colours.

Morphology

First dorsal fin rays 6-7, second dorsal fin with 1 spine and 16-19 (usually 17-18) soft rays, and anal fin with 1 spine and 15-18 soft rays. Scales ctenoid except for a few, small cycloid scales on the opercle. The breast is naked. Lateral line scales 73-83. Lateral line system with 8 transverse suborbital neuromast rows. Three rows of free neuromasts on the opercle. The height of the second dorsal fin diminishes posteriorly. Head width 1.25 depth.

Meristics for an Iranian specimen: first dorsal fin with 6 spines, second dorsal fin 1 spine and 19 soft rays, anal fin with 17 soft rays and pectoral fin with 16 branched rays. Lateral series scales 80 and transverse scale rows 20.

Sexual dimorphism

Male spawning colour is distinctive and males are larger than females.

Colour

Overall colour is pale grey with dark bands, up to 6 on the body. The first band is in front of or below the first dorsal fin and is visible from above. Intensity of bands varies with ones below the middle of the second dorsal fin and before the caudal fin origin being the most intense. The first dorsal fin has two bands, the dorsal, pectoral and caudal fins are dark while the pelvic and anal fins are pale. Males have a dark, bluish-black spawning colouration with spots and bands on the upper body becoming indistinct.

Size

Reaches 17.4 cm.

Distribution

Probably the whole Caspian Sea basin. Known from the Turkmenistan and Daghestan coasts and from recorded between Kultuk and Astara in Azerbaijan (Ragimov, 1965). Pinchuk and Miller in Miller (2004) map this species from the entire Caspian Sea including the Iranian shore but only recently has it been recorded from Iran (H. Ahnelt, et al., 2007).

Zoogeography

This species is related to Neogobius and Ponticola, more speciose genera of Ponto-Caspian gobies.

Habitat

This species has been collected down to 50 m, perhaps deeper, but little else is known of its habits. It is suspected to feed, winter and spawn in deeper waters without an onshore migration.

Age and growth

Maturity is attained in the second year of life.

Food

Unknown.

Reproduction

Fecundity reaches 1544 eggs, probably laid in a single batch. The spawning season off the Lenkoran coast is late March and early April, the earliest of all Caspian Sea gobies.

Parasites and predators

Unknown.

Economic importance

None.

Conservation

Numbers in Iranian waters and threats to this species need to be assessed.

Further work

The biology and distribution of this species in Iranian waters needs to be studied.

Sources

Based in part on Pinchuk and Miller in Miller (2004).

Iranian material: CMNFI 2006-0022, 1, 114.2 mm standard length, Gilan, southwest Caspian Sea (38º00'N, 49º30'E to 38º20'N, 50º00'E) (Ahnelt et al., 2007).

Genus Neogobius
Iljin, 1927

This genus of gobies is found in the Black and Caspian seas where there are about 14 species, some large enough to be the object of commercial fisheries. The general Farsi name for fishes in this genus is گاوماهي (gav mahi), سگ ماهي (sag mahi) or gel-ye mahi, not repeated under each species.

Berg (1948-1949) and various papers by Pinchuk (1976, 1977, 1991) recognise Neogobius as a genus but Vasil'yeva (1989) considers that the separation of Neogobius, even as a subgenus, is doubtful and refers the species to Gobius. Simonovic (1999) briefly reviews the literature on Neogobius and its distinction from Gobius. Presence or absence of a swimbladder, egg size, and presence or absence of pelagic larvae are characters which have been used to recognise genera or subgenera but these may be phylogenetically independent (Svetovidov, 1964b). Various subgenera may be recognised within Gobius such as Gobius Linnaeus, 1758, Neogobius Iljin, 1927 (type species N. fluviatilis), Apollonia Iljin, 1927 (monotypic for N. melanostomus according to Pinchuk (1991) although Vasil'yeva (1989) and Dobrovolov et al. in Charlebois et al. (1997) add the species fluviatilis on the basis of osteology and electrophoretic studies; and then later she (Vasil'eva, 1996a) places both these species in the subgenus Neogobius, again on osteological grounds), Ponticola Iljin, 1927 including such species as ratan (type species), and Eichwaldia for caspius (type species)(Eichwaldia is preoccupied by Eichwaldia Billings 1858 in fossil brachiopods, replaced by and objective synonym of Eichwaldiella Whitley, 1930). Miller and Vasil'eva in Miller (2003 - Vasil'eva's assignments) give the following subgenera, with definitions (these subgenera may eventually be elevated to genus once a thorough analysis is complete (see below); note assignments conflict in part with the above:- Neogobius (with one species, caspius), Apollonia (fluviatilis and melanostomus), Babka (gymnotrachelus, not in the Caspian Sea), Ponticola (the remainder - including species not in the Caspian Sea). Miller in Miller (2004) place Neogobius bathybius in the genus Chasar and this is followed here. Neilsen and Stepien (2006) and Stepien and Tumeo (2006) used mtDNA cytochrome b sequence data and consider Apollonia (N. melanostomus and N. fluviatilis) to be highly divergent from all other neogobiins, Mesogobius is the sister genus of Proterorhinus and a clade of these two genera is sister to Neogobius. Neilsen and Stepien (2009a) using two mitochondrial and two nuclear genes conclude that Neogobius, or in a restricted form Apollonia, consists of fluviatilis, melanostomus and caspius, Babka is monotypic (species gymnotrachelus), and Ponticola includes cyrius, gorlap, ratan and syrman among others. Mesogobius and Proterorhinus are sister groups. Tribes are also delineated. Apollonia is synonymised with Neogobius.

Pinchuk (1991) states that many of the characters used to define genera are composed for convenience in identification rather than indicating natural relationships, i.e. the characters are simply those used in keys. Ahnelt and Holčík (1996) call the taxonomy of this genus "variable, unstable and frequently uncertain" since variation between Black and Caspian Sea populations is usually very small and since there are migrating and resident marine and freshwater populations of the same species. Miller and Vasil'eva in Miller (2003) state that the genus is paraphyletic (included species do not share an autapomorphy) but retain it for convenience on morphological grounds, a practice followed here until a cladistic revision is performed.

These gobies are characterised by having an elongate body, compressed posteriorly, mouth of moderate size, 6 first dorsal fin rays, more than 10 rays in the second dorsal fin (large number of rays in the unpaired fins according to Pinchuk (1991) compared to Gobius sensu stricto), anterior nostrils tubular but not very elongate, posterior nostrils near eye, ctenoid scales of moderate size, a scaled nape and predorsal area, cheek naked, the pelvic fin anterior membrane may have obvious lateral lobes, no barbels, upper rays of pectoral fin may be free and filament-like (Pinchuk (1991) states that they are always within the fin membrane or joined), teeth conical and in a few series, back muscles extend forward almost to the eyes, tongue not notched or only slightly notched, no swimbladder in adults, 32-35 vertebrae modally (Gobius has only 28 and Proterorhinus 30-32 (Simonovič et al. (1996)), dorsal pterygiophore formula (3)22110, anal pterygiophores before first caudal haemal spine 2 or 3, large, oligoplasmatic roe, and no pelagic larvae. Miller and Vasil'eva in Miller (2003) give details of neuromast organs as follows:- infraorbital neuromasts typically in 7 transverse rows, 4 before and 3 above hyomandibular row b, and no row a. Row 7 is made up of a few to several papillae in a row descending postero-ventrally from just in front of the anterior oculoscapular pore α. Rows 5i and 6i are separated with 5i well behind the anterior end of hyomandibular row b and with 6i reaching or falling short of row b. Dorsal supraorbital rows o are separate in the dorsal midline. Hyomandibular row z ends near pore χ. Supratemporal accessory line x¹ ending anteriorly behind pore β. Anterior oculoscapuler, posterior oculoscapular, and preopercular canals present. These have the pores σ,λ,κ,ω,α,β and ρ; θ and τ; and χ, δ and ε. Anterior oculoscapular pore ρ and posterior oculoscapular pore θ well separated.

Neogobius is distinguished from the closely related genus Mesogobius Bleeker, 1874 by having a smaller number of infraorbital transverse rows of pit organs and the transverse parietal posterior rows of pit organs are separated by a wide interspace (Pinchuk, 1991).

Simonovič et al. (1996) consider this genus of gobies to be a young one as evidenced by the distribution of species in the Caspian and Aral seas which closed recently. Simonovic (1999) concludes that "Neogobius" (and Proterorhinus) evolved from a common ancestor in the Dacian Basin of the eastern Paratethys (now the Black Sea) or its tributaries during the early to mid-Pliocene, as evidenced by their absence from Adriatic, Ionian and Aegean basins. Divergence probably occurred in freshwater, riverine habitats as development is direct without a pelagic larval stage as found in marine gobiids. The hypersalinity of the isolated Black Sea in the late Miocene to early Pliocene was the causal event that led to rapid speciation of "Neogobius" and the genus retained direct development when it returned to the Black and Caspian seas. Dillon and Stepien (2001) using mitochondrial DNA suggest that the genera "Neogobius" and Proterorhinus diverged about 5.2±1.0 MYA in the late Miocene/early Pliocene from a common ancestor shared with Gobius during the isolation of the Paratethys Basin from the Mediterranean Tethys Sea. This contradicts suggestions that the neogobiins diverged from Gobius during the Quaternary interglacial connections of the Black and Mediterranean seas.

Masoumian and Aghl Mandi (2009) record Neogobius spp (presumably including Ponticola spp.) infected with Ceratomyxa caspia, a myxosporean, from the Iranian shore of the Caspian Sea.

Neogobius caspius
(Eichwald, 1831)

Common names

gel-ye mahi Khazari (= Caspian goby), gavmahi-ye Khazari, gavmahi-ye Daryaye-e Khazar.

[xval xulu in Azerbaijan; Khvalynskii bychok or Hyrcanian goby in Russian; Caspian goby].

Systematics

No major synonyms and no types known. Described in Latin from "Hab. in Caspio mari, in sinu Bacuensi" (in the Caspian Sea, in Baku Bay, Azerbaijan). Ghotb Razmjoue et al. (2008) examined the population genetic structure of this species and found no polymorphism and no differentiation in the south Caspian Sea population.

Key characters

This species is separated from other Caspian gobies in Iran by the rear nostril being slit-like and far from the eye margin. It has a comparatively small mouth.

Morphology

Head canals and free neuromasts on the body are typical of a Neogobius. First dorsal fin spines 5-7, usually 6, second dorsal fin with 1 spine followed by 14-17 soft rays. The first ray of the second dorsal fin may be elongated and branched at its tip and in such cases was counted as a "spine". Anal fin with 1-2 spines, usually 1, and 10-14 soft rays. Lateral series scales 57-71. Predorsal area and nape scaled, anteriorly reaching to the orbit (postorbital section of the supraorbital canal of the cephalic lateral line system). Anteriormost scales cycloid. Scales have a diamond-shaped pattern on the flank. Individual scales are squarish with the upper and lower margins straight to slightly rounded or, more rarely, each scale has an overall rounded shape. The posterior margin has two straight edges meeting at the posterior centre. The posterior margin bears ctenii. The anterior margin is wavy where the radii terminate at indentations and there is a central protuberance. Moderately numerous radii radiate anteriorly from the central point of the posterior margin, occupying the entire anterior field and spilling into the lateral fields. Circuli are fine. There is a dermal papilla on the posterior edge of the gill chamber, just under the gill cover. The gill rakers are short anteriorly and posteriorly but vary in length and the longer central rakers reach the second adjacent raker when appressed. Rakers are commonly forked or even antler-like. Dorsally the smallest rakers are difficult to distinguish from mouth cavity tubercles and only definite rakers were included in the count. The pelvic fin anterior membrane has pointed lobes. The gut is an elongate s-shape with convolutions or twists along its length. The genital papilla is bifurcated at the tip.

Meristics for Iranian specimens: first dorsal fin spines 5(1), 6(37) or 7(2); second dorsal fin soft rays 14(2), 15(10), 16(27) or 17(1); anal fin soft rays 11(2), 12(25) or 13(13); pectoral fin rays 17(6), 18(29) or 19(5); lateral series scales 60(2), 61(4), 62(6), 63(8), 64(10), 65(6), 66(1), 67(1), 68(1) or 70(1); total gill rakers 8(1), 9(3), 10(17), 11(14), 12(4) or 13(1); and total vertebrae ?.

Sexual dimorphism

Colour differences are given below.

Colour

Overall colour is a dark grey or grey-brown with a clearly contrasting white to pearly white belly and lower head surface. The back may have 7-8 dark brown or grey saddles. The flanks have 6-10 obscure dark spots. The first dorsal fin has 2-4 dark brown stripes and a black spot over the last three rays. The black spot may not be very evident and merges with the general background pigmentation. There are no clearly defined spots on the fins although the rays are brown in all but the pelvic and anal fins. The anal and pelvic fins are pearly-white. The caudal fin has a narrow whitish transparent edge. The iris has a narrow golden ring. The genital papilla is white or grey. The peritoneum is silvery-brown in preserved specimens.

Breeding males are black all over, often including the margin of the first dorsal fin. First dorsal fin ray tips may be yellowish. The belly is whitish to pale grey in front of the pelvic fins. There is a dark spot at the end of the first dorsal fin. The second dorsal fin has a narrow colourless margin but fin tips are not extended into free ends as obviously as in some Neogobius species. All fins have a fringe effect although this is not well developed in the first dorsal fin. The caudal fin has a colourless or whitish margin. The dorsal fin spot is lost temporarily after spawning.

Size

Reaches 20.2 cm.

Distribution

This species is found in the Caspian Sea and is recorded between Kultuk and Astara in Azerbaijan (Ragimov, 1965). In Iran records are from both the southwestern, south-central and southeastern Caspian Sea, and Gorgan Bay (Abdoli and Naderi, 2009).

Zoogeography

Endemic to the Caspian Sea.

Habitat

Found throughout the Caspian Sea but does not enter fresh water. It is found on sand or pebble bottoms, less often on stones and rarely on soft mud. They tend to remain inshore until the winter when temperatures fall although high summer temperatures may drive them into deeper and cooler water for a short period (Pinchuk and Miller in Miller, 2003).

Age and growth

Sarpanah Sarkohi et al. (2010) found fish to reach age 5 years in the Iranian Caspian Sea sample sites listed below.

Wikimedia Commons

Common names

gavmahi-ye gerd (= round goby), gel-ye mahi gerd (= round goby), gavmahi domgerd, gavmahi-e-domguerd, sebele.

[xazar kirda xulu in Azerbaijan; Kaspiiskii bychok-kruglyak or Caspian round goby in Russian; black spotted goby].

Systematics

Gobius melanostomus was originally described from Sevastopol and Balaklava, Ukraine, on the Black Sea. No types known.

Gobius affinis Eichwald, 1831 described in Latin from "Hab. in Caspii maris sinu bacuensi, balchanensi" (Baku and Balkhan bays in the Caspian Sea, no types known) and Gobius sulcatus Eichwald, 1831 described in Latin from "Hab. in Caspii maris sinu balchanensi" (Balkhan Bay in the Caspian Sea, no types known), are synonyms. The Caspian Sea population was referred to Neogobius melanostomus affinis (Eichwald, 1831) but subspecies are no longer recognised (Iljin, 1956; Pinchuk, 1976). However, Brown and Stepien (2008) conclude on DNA evidence that Black and Caspian Sea populations diverged ca. 350,000 years ago and this supports subspecies separation.

Key characters

Pelvic fin anterior membrane with rounded and shallow lateral lobes; lobes not more than one-sixth width of anterior edge of membrane, or lacking entirely; nape scaled and at least anterior nape scales cycloid; first dorsal fin with large dark spot at rear; and lateral series scales usually 49-55.

Morphology

This species is separated from other Caspian gobies in Iran by having a small mouth, rounded, shallow, poorly-expressed lobes to the pelvic anterior membrane, scales in lateral series 41-59 (usually 47-55), generally at the low end of this range, mid- and anterior nape scales are cycloid as are most of those on the gill cover, throat, pectoral in bases and part of the abdomen, the pelvic disc is 0.6-0.8 pelvic base to anal fin length, the jaw angle is below the level of the anterior part of the eye, the posterior nostril is close to the eye margin, and the first dorsal fin has an obvious dark spot posteriorly.

First dorsal fin spines 5-8, usually 6, second dorsal fin with 1 spine and 11-18 soft rays, anal fin with 1 spine and 9-14 soft rays, and pectoral fin with 16-20 branched rays. Scales appear as diamond-shaped on the flank since the posterior margin has two straight edges coming to a central point. However scales can be quite rounded even adjacent to those forming a diamond pattern. The posterior margin bears ctenii. Dorsal and ventral margins are rounded and the anterior margin is indented above and below a central protuberance. Radii radiate anteriorly from the centre of the posterior margin. Circuli are fine. Gill rakers 9-13, presumably on lower arch only, see below. Gill rakers may reach the second adjacent raker when appressed and although usually regular can be branched and variable in size along the arch. Vertebrae 31-34.

Head depth at the eyes is 0.9-1.2 head width between the upper origins of the opercles. The interorbital width is 0.8 to slightly less than eye diameter. The snout is longer than the eye, 1.1-1.4 times. The upper lip narrow slightly rearward and is about half the lateral preorbital area (between lip and eye). Caudal peduncle depth is two-thirds its length. The tongue is truncate or slightly notched. The posterior teeth on the dentary bone are smaller than the anterior teeth and all are blunt. Pharyngeal teeth are molariform, adapted to crushing molluscs. The anal papilla is bifurcated at the tip. The gut is short and roughly s-shaped with some convolutions, particularly on the posterior section.

The chromosome number for "N. m. affinis" is 2n=46 with 46 chromosomal arms (Ráb, 1985; Vasil'ev and Grigoryan, 1993; Simonovic, 1999).

Meristics for Iranian fish:- first dorsal fin spines 5(6) or 6(34); second dorsal fin soft rays 12(1), 13(2), 14(18), 15(18) or 16(1); anal fin soft rays 10(3), 11(17), 12(19) or 13(1); total pectoral fin rays 17(11), 18(28) or 19(1); lateral series scales 48(1), 49(3), 50(8), 51(4), 52(8), 53(4), 54(5), 55(4), 56(2) or 57(1); total gill rakers 11(5), 12(15), 13(11), 14(7) or 15(2); total vertebrae ?.

Sexual dimorphism

Females are smaller than the male. Mature males have larger dorsal, pectoral and anal fins, swollen cheeks, and colour is different (see below).

Colour

Overall colour is yellowish-grey or brownish-grey (fawn) with 8-9 large, dark brown, blue-grey to black flank blotches. There are 4 saddles across the back. The first dorsal fin has a black blotch posteriorly over the last two rays (and sometimes on the interradial membrane between rays 4 and 5), and the blotch or spot may have a white border in juveniles. The spot can be absent as reported by Jude (1997) for fish introduced to the North American Lake Erie. The sides of the head have oblique, curved bands or a reticulate pattern of a rusty to gingery tint on a bluish-grey background. The pattern is darker on the opercle and snout. The first dorsal fin may be tinged green and has 3 rusty-brown bands and a narrow margin may be a rusty or yellowish colour. The second dorsal and caudal fins may have a light margin even in non-spawning individuals. The second dorsal fin has 3-4 rows of small rusty spots. The caudal fin also bears rusty spots anteriorly but not in very definite rows. The anal fin is grey to dark brown. The pectoral fin lacks spots and is almost colourless but may be tinged with yellow. The pelvic disc is grey with a rusty colour in the centre. The genital papilla is grey or unpigmented. The iris is yellow to orange. The peritoneum is a silvery brown.

Colour varies with habitat. In bays with algal growth fish are darker, blue-grey tints are lost, there are more yellowish-brown colours and there is an increase in number and size of dark-brown spots. Others may have an olive-green tint.

When spawning, males are charcoal black overall, sometimes with a bluish tint, and with indistinct yellow spots. The dorsal, caudal and anal fins are white-edged or yellow, although the first dorsal margin can be black and there may be practically no margin to the anal fin. The black spot on the first dorsal fin can still be seen against the light. There are no free tips to fin rays according to literature reports but Iranian specimens have all fin tips separated to form a fringe.

The young are a slate grey overall with a mottled and blotched flank. The mid-flank blotches may form a series of about 6. There is a spot at the upper base of the pectoral fin. The dorsal fin spot is centred on the membrane between the last two rays but spills over onto the adjacent membranes, particularly the posterior one. Fins have pigment on the rays and membranes with no clear pattern. The dorsal fins are darker than the anal which is darker than the pectoral or pelvic. There is a bar from the lower eye margin to the upper lip just anterior to the mouth corner.

Size

Reaches 29.0 cm total length. Freshwater fish are smaller than marine ones.

Distribution

Found from the Aegean to the Black and Caspian seas. Introduced to the Aral Sea in the 1950s but increasing salinity in the 1980s eliminated the population. Now in the Baltic Sea via rivers and canals or in ship ballast. Also present by introduction in the Great Lakes of North America where first reported in 1990, apparently from several sources (Brown and Stepien, 2006).

Reported from a wide range of rivers along the Caspian coast of Iran including the Gorgan, Tonekabon, Safid, Dyusan, Shimrud, Chemkhaleh, Rud-e Sere, Kargan, Navarus, Chalus, Babol and Haraz rivers, the Anzali Mordab, Gorgan Bay, the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea (Holčík and Oláh, 1992; Abbasi et al., 1999; Kiabi et al., 1999; Abdoli, 2000; Jolodar and Abdoli, 2004; Abdoli and Naderi, 2009). Apparently absent from the Atrak River in Iran and of uncertain presence in the Aras River (Abdoli and Naderi, 2009).

Zoogeography

See genus account above.

Habitat

This species is found in inshore waters at depths to about 20 m, sometimes to 70 m or even 200 m in deeper sea areas in winter, on rock, gravel, shell, sand or silt bottoms. Aquarium specimens are seen to hide in crevices and under rocks. In the Caspian Sea, it may be found among eelgrass, Zostera. It also enters rivers. Larvae live near the bottom. The species prefers littoral areas where wave action keeps oxygen levels high and decaying material is reduced. It leads a sedentary life (Moskal'kova, 1996). It may be found from fresh waters to salinities of 40.5‰ from -1 to 32°C, and respiring through the skin can tolerate low oxygen conditions from 0.3-0.9 ml/l (Moskal'kova, 1996; Jude, 1997).

In the North American Great Lakes basin, where it is an exotic, this species prefers rocky habitats and is more active during the day than the night. The mean density in one river was approximately 7 gobies/sq m and can reach as high as 90 gobies/sq m since they aggregate. This goby has a high site fidelity in mark-recapture studies (Ray, 1997; Ray and Corkum, 1997a).

The gobies can tolerate a flow of 0.34 m/s for 3-4 minutes but at higher levels they retreat to the bottom and brace themselves against the current using the pectoral fins.

The onshore spawning migration in the southern Caspian Sea occurs in spring, later than P. syrman and P. gorlap. A spawning area is chosen on the basis of stones being present rather than depth. Larger males approach the shore first. There is an offshore movement as winter begins and in the hottest part of summer.

Age and growth

Maturity is attained in the second year by females and in the third year by males but may be as early as 1 year. Life span can exceed 5 years for females. Males die after spawning. Faster growth results in a shorter life span. At the end of the first year of life they can reach 5.5-6.0 cm (Moskal'kova, 1996). In North America, populations of this exotic are dominated by age one fish (MacInnis and Corkum, 1997a). Growth is slower in North America and maximum size is less than in its native habitat, probably because temperatures are lower than in Europe (Jude, 1997). Abdoli et al. (2006) examined fish from the Gomishan and Miankaleh wetlands and found a length (L)-weight (W) relationship of W = 0.0091L^3.17 for males, 0.0249L^2.7 for females and 0.0112L^3.08 for sexes combined.

Food

Abd Elahpour Biria et al. (2010) examined samples from 0-5 m, 5-10 m and 10-15 m from Astara, Anzali and Chaboksar coasts. Molluscs and benthic crustaceans were the preferred foods, feeding decreased with increased temperature, there was no difference in feeding intensity between sexes but some differences were noted based on station and sampling depths.

Molluscs predominate with significant amounts of crustaceans in the north Caspian Sea but this can vary annually with crustaceans becoming predominant. They feed most heavily in the post-spawning period in July and August (Opalatenko, 1979). Other important foods are bivalves, such as zebra mussels, snails, polychaetes, chironomids, other aquatic insects, goby eggs and small fishes. Attached clams and mussels are bitten off the substrate by the large jaw teeth and crushed by the pharyngeal teeth (Moskal'ova, 1996). Molluscivory is also documented for Danube River populations (Simonovič et al., 2001) and for Baltic Sea populations (Skora and Rzeznik, 2001) and molluscs appear to be the preferred diet wherever this species is found. An exception may be the southern Caspian Sea where one study found crustaceans to predominate (Pinchuk et al. in Miller, 2003).

In the Caspian Sea, introduced species, such as crabs, the worm Nereis diversicolor and the mollusc Abra ovata, are also eaten (Kosarev and Yablonskaya, 1994). Iranian specimens contain plant fragments, mollusc shells, shrimps, fish remains, aquatic insects and polychaetes.

In North America, immature round gobies are the most successful predators on round goby eggs. Round gobies are said to be aggressive and will take a baited hook. However this goby may need to be stationary to detect prey. Nocturnal feeding occurs. The blunt teeth are indicative of a primarily mollusc diet.

Experimental studies in North America have shown this species to prefer individual and clumped zebra mussels to other foods such as sphaeriid clams. Feeding rates vary between 36 and 47 mussels (4.5-12.5 mm long) per day for fish 6-10 cm long, over 100 mussels per day when the mussels are smaller than 4 mm (Ghedotti et al., 1995). Mussels can remain in the mouth and pharynx for less than one hour to over 12 hours; shells are then split and ejected. However some are crushed and passed through the digestive tract. In the upper Detroit River, Canada, round gobies eat zebra mussels (58%), snails (6%) and other invertebrates (36%) such as aquatic insects, softshelled crayfish and zooplankton. In laboratory studies, round gobies ate an average of 1 g of mussels in 24 hours, smaller mussels being preferred (Ray and Corkum, 1997b). However, field studies in Lake Michigan show that round gobies are unlikely to remove zebra mussels (also a pest in North America) from a habitat (Djuricich and Janssen, 2001). These gobies are also predators on lake trout eggs under laboratory conditions in North America (Chotkowski and Marsden, 1999). They are also reported to eat sturgeon eggs in North America.

Reproduction

There is a movement inshore to waters about 0.2-1.5 m deep for spawning, males preceding females. Spawning takes place at the end of April to September in near shore areas of the north Caspian Sea and over a similar period in the Baltic Sea. Iranian specimens have well-developed testes on 10 April and spawning may occur earlier than in the North Caspian. There may be repeat spawning, up to 6 times every 18-20 days, as indicated by captive specimens. Peak spawning occurs at 15°C (range 10-30°C). Eggs are attached to or under rocks, in cavities, under logs or in such objects as cans and are aggressively guarded by the male. Early maturity, a very long spawning season and aggressive defense contribute to high egg, larvae and fry survival. The male prepares the nest site with a secretion from a cement gland which is coated over the site. As the female lays each egg, it is glued to the underside of the nest cavity roof in single layer rows. Egg clutches can be transported on the hulls of ships (Ahnelt et al., 1998). Fecundity reaches 6,177 eggs. Eggs are pale yellow, orange or pink, with red pigmentation. the eggs are ovoid with a sharp apex and measure 3.9 by 2.2 mm. Details of development are given by Moskal'kova (1996).

In North America, the species has been shown to be a multiple spawner with an extended reproductive season and male guarding of eggs (MacInnes, 1997). Here maturity occurs as early as year one and 43 mm standard length, a year earlier than in their natural habitat. Spawning extends from May to early August. Mean fecundity is 198 eggs. Each nest is utilised by large numbers of females since as many as an estimated 9462 eggs were found in each artificial nest site (MacInnis and Corkum, 1997b). Such a nest site can lose 50-70% of the eggs to predators while smaller clutches lose few eggs.

Jude (1997) notes that in North America some males do not defend a nest, the reason being unknown. This may well be due to such factors as availability of suitable spawning sites, large size or aggressiveness. He reports that after reaching a large size, males spawn once and then die, although females spawn up to six times through spring and summer, about every 20 days. Elsewhere males guard the nest from predators and fan the eggs to oxygenate them and to reduce siltation and fungal infection. Males will eat infected and unfertilised eggs. Males defend the nest by flaring the gills, spitting sand, darting at nearby intruders, biting, and growling for 1.0-1.5 seconds loud enough to be heard 10 m away. Nest sites in North America may be as deep as 7 m (Corkum and Wickett, 1998).

Males make several sounds including one attracting females to nest sites and another to intimidate other males. Females respond to male calls by a quieter sound (Jude, 1997).

Parasites and predators

Fil mahi (Huso huso), chalbash (Acipenser gueldenstaedtii), uzun burun (Acipenser stellatus), mash mahi (Aspius aspius), ordak mahi (Esox lucius), suf (Sander lucioperca) and seals are predators. Daghigh Roohi and Sattari (2004) record Dichelyne minutus and Corynosoma strumosum from this species in the southwestern Caspian Sea of Iran. Sattari et al. (2004; 2005) surveyed this species in the inshore area of the Caspian Sea, recording Dichelyne minutus. Sattari et al. (2007) report the nematode Eustrongylides excisus for this species in Iranian waters.

Economic importance

Robins et al. (1991) list this species as important to North Americans. Importance is based on its use in aquaria, as food and because it has been introduced outside its natural range. It is caught by anglers in some parts of the Caspian Sea basin.

It is present in the North American Great Lakes and is expanding (Ray and Corkum, 2001; Clapp et al., 2001; Jude et al., 1992; Jude, 2001). It is an introduction from the ballast waters of ships from multiple sources, perhaps including the Black Sea (Dillon and Stepien, 2001). Round gobies may displace native fish, compete for food and eat their eggs and young, and are the target of major efforts to study and contain them (Arrigoni and Berg, 2001; Charlebois et al., 2001; Diers et al., 2001; French and Jude, 2001; Janssen and Jude, 2001; Kaur et al., 2001; Schreier et al., 2001; Wolfe, 2001). They may also accumulate and pass on large concentrations of such chemicals as PCBs to sport fishes in North America (Jude, 1997). An extensive literature is now available on the Great Lakes populations. A summary of invasions and biology in North America and Europe is given in Kornis et al. (2012).

It is an important food species in the Black Sea marketed fresh and formerly canned in tomato sauce. In the Sea of Azov in 1950-1960, gobies made up the bulk in local fisheries and round gobies comprised almost 90% of a catch exceeding 90,000 t (Moskal'kova, 1996). Freyhof (2011) records that this species is salted, dried and consumed with beer in the Azov Sea area. Commercial catches in the Caspian Sea have comprised up to 88.2% of goby catches but pollution has severely depleted stocks (Pinchuk et al., 2003).

Conservation

Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include medium numbers, habitat destruction, widespread range (75% of water bodies), absent in other water bodies in Iran, and absent outside the Caspian Sea basin (as N. m. affinis).

Further work

Biology in Iran has not been studied as well as elsewhere.

Sources

Charlebois et al. (1997) and Pinchuk et al. (2003) give general reviews of biology and are excerpted briefly above.

Iranian material:

Neogobius pallasi
(Berg, 1916)

Common names

gavmahi-ye tireh (= dark goby), gel-ye mahi rudkhanehai (= river goby), gavmahi-ye sheni, sebele.

[gumlur xulu in Azerbaijan; Kaspiiskii bychok-pesochnik or Caspian sand goby, rastrepka (= a person with untidy hair in reference to the fringed ends of the fin rays), chernysh (= darkie), khylak (when emaciated), all in Russian; Caspian monkey goby].

Systematics

Gobius fluviatilis was originally described in part from near the mouths of rivers falling into the Black Sea and similarly the Caspian Sea. No types are known. Neogobius fluviatilis pallasi (Berg, 1916) was the subspecies of the Caspian Sea basin. Kottelat and Freyhof (2007) recognise pallasi as the Caspian Sea species and restrict fluviatilis to the Black Sea basin. The type locality is the Caspian Sea, mouths of the Ural and Volga and syntypes are in the Zoological Institute, St. Petersburg under ZISP 2195, 2204, 23137, 30729, 30736, 30738, 30919, 30920, 30924-26. 33182, 34276, 34277 (Eschmeyer's "Catalog of Fishes", downloaded 23 August 2007).

Abd Elahpour Biria et al. (2009) examined fish from 4 localities on the Gilan coast using morphometric characters and found 3 different populations in Astara, Anzali and Chamkhaleh and Chaboksar.

Key characters

Pelvic fin anterior membrane with rounded and shallow lateral lobes. less than one-fifth rear edge width; pelvic fin disc 0.9 to more than distance to anal fin origin; nape with ctenoid scales; first dorsal fin without large dark spot (except in juveniles); lateral series scales usually 55-70; pelvic fin membrane anterior lobes small, rounded; angle of jaw anterior to orbit; and two transverse infraorbital papillae rows below longitudinal hyomandibular row b.

Morphology

The head width (between upper origins of opercles) is about equal to head depth (at eyes). The interorbital distance is not more than 0.75 eye diameter. The top of the head and the occiput are scaled with ctenoid scales. The upper lip is expanded towards the mouth corners, sometimes narrowing at the very end. The angle of the jaws reaches back at a level between the eye and the posterior nostril. The snout is longer than the eye diameter (1.6 times). The upper lip is not swollen at the angle, and measures 0.4-0.6 lateral preorbital area (between lip and eye). The first dorsal fin is high with an acute anterior profile, the first branched ray about twice as long as the penultimate ray. The pelvic fin has small, rounded lateral lobes (< 0.2 rear edge width) and almost reaches the anal fin (0.9 distance) or extends beyond the anal fin origin. The caudal peduncle depth is 0.5-0.6 length.

First dorsal fin spines 5-7, usually 6, second dorsal fin with 1 spine followed by 11-18, usually 15-17, soft rays, anal fin with 1 spine and 11-17 soft rays, usually 13-15, and pectoral fin rays 16-19. Lateral line scales 49-69, mostly 52-65. Gill rakers 6-10. Vertebrae 31-35. The chromosome number is 2n=46, with 46 acrocentric chromosomes and 46 chromosomal arms (Grigoryan and Vasil'ev, 1993; Klinkhardt et al., 1995; Simonovic, 1999).

N. pallasii is distinguished by the dorsal fin spot in young fish and an average number of lateral series scales being 53 as opposed to 62 for Black Sea fish.

Sexual dimorphism

See under colour. Males become slimmer at spawning and their are morphometric differences between the sexes (Pinchuk et al. in Miller, 2003).

Colour

Overall colour is pale and sandy, in cantrast to other gobies. On the flanks and over the back there is a series of 8-9 brownish elongate spots or blotches. The belly, lower head and genital papilla are pearly white. A dark bar runs from the eye antero-ventrally to the lip. The first dorsal fin has a dark spot posteriorly, although it may be absent in some adults, and is characteristic of the former subspecies pallasi, and found in small fish in the southern Caspian, persisting in adults in the northern Caspian (Pinchuk et al. in Miller, 2003). The first dorsal fin has 1-2 rows of grey to black spots and the second dorsal fin has 1-3 rows of pale grey spots. The caudal, anal, pectoral and pelvic fins are mostly grey on the rays and immaculate.

Breeding males become black or blue-black with the dorsal, caudal and anal fins bearing a yellow-orange margin. Some fish have a very narrow colourless margin to the pectoral and pelvic fins. The second dorsal fin may only be yellowish on its first ray, the remainder being white and the caudal margin may be colourless. Rays in the second dorsal fin of breeding males become extended into free tips.

Size

Reaches 24 cm total length although in the Caspian the largest fish are 16.0 cm males (Pinchuk et al. in Miller, 2003).

Distribution

Found in the Caspian Sea and its basin. In Iran, it is found in rivers along the Caspian coast including some upper reaches, the Aras River middle reaches and its tributary the Qareh Chai, the Anzali Mordab, Gorgan Bay, at Bandar Gaz, in the Gorgan, Madarso (or Madar Su), Tajan, Babol, Haraz, Sardab, Tonekabon, Pol-e Rud and Safid rivers (including their middle to upper reaches such as the lower Qezel Owzan and Shahrud of the Safid River basin), the southeast Caspian Sea, the southwest Caspian Sea and the south-central Caspian Sea (Shamsi et al., 1997; Abbasi et al., 1999; Kiabi et al., 1994; 1999; Abdoli, 2000; Abdoli and Naderi, 2009). Note that Abdoli (2000) records it from the upper Atrak River in contrast to earlier authors.

Zoogeography

The southern Caspian Sea and its tributary rivers is inhabited by a distinct subspecies, presumably on account of isolation from populations in the Black Sea. See genus account above.

Habitat

This species is found in inshore brackish waters and enters rivers. Salinities up to 46.9‰ are tolerated in marine bays. It is found down to 25 m although depths of 0.5-10 m are preferred, shallower in spring (0.5-5.0 m), slightly deeper in summer and deeper still in fall (5-10 m)(Pinchuk et al. in Miller, 2003). It is found over sand, mud and sandy-shelly bottoms. In the Madarsoo stream of Golestan National Park, abundance ranged from 0.1 to 0.75 fish per sq m and biomass from 0.21 to 4.88 g/m² (Abdoli et al., 2002). Floods in this stream reduced the population, presumably through destruction of the substratum and its food supply. Smaller fish were caught in riffles while larger fish lived close to to the river bank in depths up to 0.5 m. Abdoli and Rahmani (2001) found this species to represent 95% of the goby catch in the Madarsoo stream, with N. melanostomus occupying the remainder.

Age and growth

Sexual maturity is attained at 2 years of age (9-12 cm for males, 8.5-10.5 cm for females) but may be as early as 1+ year (5.5 cm), particularly in the Caspian. Spawning males near Bandar-e Anzali were 12.4-15.2 cm long. Life span is 6 years but perhaps only 2+ years in the Caspian (Pinchuk et al. in Miller, 2003). Abdoli et al. (2002) found a sex ratio of 1 male to 3 females in the Madarsoo stream. Patimar et al. (2008) reported 5 age groups in fish from the Zarrin-Gol River in the eastern Alborz Mountains. Maximum total lengths were 12.1 cm in males and 10.8 cm in females, both 4+ years old. Fish aged 2+ and 3+ years were the most frequent in the population. sex ratio was equal and growth was negative allometric. Condition factor was highest in early September. Males showed a higher growth rate than females after age 1+ years. Abdoli et al. (2006) examined fish from the Gomishan and Miankaleh wetlands and found a length (L)-weight (W) relationship of W = 0.0059L^3.291 for males, 0.0128L^2.92 for females and 0.0057L^3.29 for sexes combined.

Food

Diet items include crustaceans with lesser amounts of molluscs, polychaetes, chironomids and small gobies in the north Caspian Sea. They feed most heavily in the post-spawning period in July and August (Opalatenko, 1979). The quantity of amphipods eaten increases with age while the amount of mysids decreases. Introduced species, such as crabs, the worm Nereis and the mollusc Abra, are also eaten (Kosarev and Yablonskaya, 1994). In the Madarsoo stream of Golestan National Park in Iran, Ephemeroptera and Chironomidae are the most important food items but also included Trichoptera, other aquatic and terrestrial insects, crustaceans (including freshwater crabs), arachnids, worms and snails (Abdoli and Rahmani, 1999; Abdoli and Rahmani, 2001; Abdoli et al., 2002). Alavi Yeganeh and Kalbasi (2006) found fish in shallow water at Noor fed on amphipods, fish larvae, barnacles, palaemonid shrimps, mytilid bivalves, xanthid crabs, cardid bivalves, fish eggs and oligochaete worms, in order of preference. Diet varied with season, males feeding less during spawning for example Patimar et al. (2008) found the most frequent food items of fish in the Zarrin-Gol River were trichopterans, molluscs, chironomids and gammarids.

Reproduction

Spawning can take place from late April to September, varying with locality. Peak spawning in the Volga River delta is in May. Spawning is recorded at 18-26ºC, 20-28‰ and 0.5-1.3 m (Pinchuk et al. in Miller, 2003). In the Madarsoo stream of Iran, spawning peaked in March with an absolute fecundity of up to 532 eggs (Abdoli et al., 2002). Fecundity reaches 1025 eggs in the southern Caspian (perhaps 12,800 eggs elsewhere) and egg diameter 2.1 mm. Yellow-amber or pale pink eggs are laid on or under stones and plants. Nests are excavated by the male under natural or artificial objects. The male defends the nest and larger males are more successful. However, the stress associated with constant defense against predators and competing males leads to extreme emaciation. Nests contain more eggs than fecundity would indicate suggesting that more than one female lays eggs in a nest (Pinchuk et al. in Miller, 2003). Patimar et al. (2008) found the Zarrin-Gol River population to have an average absolute and relative fecundity of 508.47 eggs and 61.27 eggs/g. The reproductive season was March to April.

Parasites and predators

Pazooki and Aghlmandi (1998) found the nematode Dichelyne minutus infecting the intestine of 6.6% of fish examined from the Tajan River in Mazandaran. and Sattari et al. (2002) and Sattari (2004) records the presence of the nematode, Eustrongylides excisus, in this species. This parasite can damage muscles in commercial species and render them unsuitable for sale. Fil mahi (Huso huso), chalbash (Acipenser gueldenstaedtii) and suf (Sander lucioperca) are predators. Sattari et al. (2004; 2005) surveyed this species in the inshore area of the Caspian Sea, recording Eustrongyloides excisus and Dichelyne minutus. Daghigh Roohi and Sattari (2004) record Eustrongylides excisus, Dichelyne minutus and Corynosoma strumosum from this species in the southwestern Caspian Sea of Iran.

Economic importance

This is the most economically important goby in the north Caspian Sea according to Berg (1948-1949). Iljin (1956) considered this an error; it is the most numerous species but commercial fishing does not occur there. Pinchuk et al. in Miller (2003) state however that it comprised 54% of the entire goby catch, although only 7.7% in southern Dagestan. It is food for sturgeons and Sander lucioperca.

Conservation

Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include abundant in numbers, habitat destruction, widespread range (75% of water bodies), absent in other water bodies in Iran, and absent outside the Caspian Sea basin (as N. f. pallasi).

Further work

On of the better known gobies in Iran but could still use work on its biology.

Sources

Genus Periophthalmus
Bloch and Schneider, 1801

This mudskipper genus is found in the eastern Atlantic, Indian and western Pacific oceans. There are 12 species in the genus as yet undefined by a synapomorphy (Murdy, 1989). The pelvic fins are only partially united or may be totally separate. There are usually 12-14 pectoral fin rays, 4-17 first dorsal fin spines, and 8-13 second dorsal and anal fin rays. Scales are cycloid and cover the whole body and head except for the snout, isthmus and interorbital region in most species. Caninoid teeth are present in both jaws as a single row, with the anterior ones larger and pointed. The eyes are erectile and have a dermal cup covering the lower portion. There is a median fleshy ridge anterior to the eyes.

Mudskippers are found on muddy shores associated with mangroves but also venture into rivers. They spend much time out of the water.

Periophthalmus waltoni
Koumans, 1955

Common names

gel-cheragh (= mud-eater, mud-grazer), mahi-sag (= dog fish), gel khorak.

[shelambo, abou-shlembo or abu-shelamboo in Arabic; gullo in Pakistan; dark-blotched mudskipper, Walton's mudskipper, spotted mudskipper].

Systematics

This species was originally described from Iraq and Pakistan. The type locality is unclear as the information given by Koumans (1955) gives more than one locality, as follows:-

"Habitat.-Mesopotamia, Karachi.
I have seen 2♂ and 2♀. These were from the following localities:-
                 Indian Museum Collection.
Fao estuary of the Shatt-el-Arab, Mesopotamia, ♀        H. J. Walton.
Karachi ♂ and ♀                                                          W. D. Cumming.
Mouth of Shatt-el-Arab ♂                                             W. T. Blanford.".

The type locality could be Fao and the holotype is the female specimen caught by H. J. Walton and named for him, the remainder being paratypes - by implication. Alternatively and probably correctly, these are all syntypes as no holotype was formally designated. The date of publication of Koumans work is 1955, not 1941 as cited by Murdy (1989).

This species has been confused with Periophthalmus koelreuteri (Pallas, 1770), itself a synonym of Periophthalmus barbarus (Linnaeus, 1766) according to Murdy (1989). P. barbarus does not occur in the Persian Gulf region. P. waltoni has been placed in the synonymy of P. koelreuteri in works on Persian Gulf fishes, e.g. by Relyea (1981), but the revision by Murdy (1989) is followed here. Another mudskipper species listed in Coad (1991b), Periophthalmus weberi Eggert, 1935, should be deleted from the list as Murdy (1989) does not report it from the Persian Gulf.

Two syntypes of Periophthalmus waltoni are in the Rijksmuseum van Natuurlijke Historie, Leiden (RMNH 17004) and 4 syntypes are in the Zoological Survey of India, Calcutta (possibly lost) (Murdy, 1989). However, this is more fish than listed in Koumans (1955).

Key characters

The pelvic fins are totally united into a sucker with a well-developed basal membrane or frenum (absent in P. barbarus). The anal fin base and second dorsal fin base are 27% or less of standard length and there are no canine teeth internal to the lower jaw symphysis in contrast to Boleophthalmus, the other mudskipper of southern Iran.

Morphology

First dorsal fin spines 10-14, second dorsal fin with 1 spine and 12-14 soft rays. Anal fin with 10-13 soft rays. Pectoral fin rays 13-15. Scales in lateral series 90-121, predorsal rows 27-37. The upper jaw has 4-5 anterior teeth on each side much larger than lateral teeth. Upper jaw teeth 19-28, lower jaw teeth 17-23. Gill rakers 9-16, mean 11, on each arch, triangular in shape with 3-4 spines at the top of each raker (Barak et al., 1994). The first dorsal fin lacks elongate spines and is slightly rounded. The dorsal fins are not connected by a membrane. The gut shortens with growth in terms of body length indicative of a carnivorous habit (Barak et al., 1994).

Sexual dimorphism

Females have a lozenge-shaped first dorsal fin (i.e. anterior 6 spines equal in height followed by abruptly shortened ones) with a height less than body depth; in males this fin equals body depth.

Colour

The overall colour is a light grey-brown. The flank bears blotches which, below the soft dorsal fin, take on the form of 8 short bars and there is a scattering of small silvery or white dots. Ventrally the spots form roughly transverse silvery stripes. The head top is also blotched and the sides bear a few small white dots. There are 7 irregular black blotches along the back. The first dorsal fin is dusky brown to light grey and its margin is yellowish between spines 1 to 8 and dark just below this except for the posteriormost 3-4 spines. There is a series of light spots on each interray membrane on the basal half of the fin. The second dorsal fin is dusky brown, with a pale margin, followed by a black stripe, and then with a white spot at the middle of each membrane thus forming a horizontal dotted line along the mid-fin. The caudal fin is a dusky brown, darker basally. There are 3 black blotches on the caudal peduncle. The pectoral fins are a light dusky brown on the rays with the membranes on the upper half pale with dark, brownish streaks in mid-fin, and a whitish margin is present. The pelvic fins are blackish with a reddish-brown or pale margin.

Size

Reaches 20.0 cm total length (Mhaisen and Al-Maliki, 1996).

Distribution

Found from the Persian Gulf to Pakistan. Reported from the Shatt al Arab, Iraq near Iranian Khuzestan by Khalaf (1961), Al-Nasiri and Hoda (1975b, 1976), Al-Hassan et al. (1989), and Hussain et al. (1989; 1997). Specimens believed to be this species have been reported from Iranian fresh waters but no specimens have been examined. Holly (1929b) records this species from the type locality of Barbus baschakirdi in the Bashakird Mountains (see Cyprinion watsoni). The Museum of Comparative Zoology, Harvard has a Periophthalmus species recorded from Manyuhi on the Shatt al Arab in irrigation ditches (MCZ 149602) but the identity of this specimen needs to be confirmed.

Abdoli (2000) maps this species from the Arvand River in the Tigris River basin, the lower Zohreh (= Hendijan), lower Helleh and Mand rivers in the Gulf basin, the Kul and Mehran rivers of the Hormuz basin, and the lower reaches of rivers of the Makran from the Jagin to the Bahu Kalat.

Zoogeography

This species has ready access to the sea and can colonise rivers along the Iranian coast.

Habitat

The habitat and behaviour of this species is similar to Boleophthalmus dussumieri (q.v.; Tytler and Vaughan (1983) review behaviour of this species in Kuwait, their Periophthalmus koelreuteri being this species according to Murdy (1989)). However it favours areas of mud which are drier on the upper and middle regions of the shore. The burrow is Y-shaped with two entrances and a depth of 30 cm in mud. Fish occupy several burrow systems within a 2-3 m home range (Clayton and Snowden, 2000). Young first appear on mud flats in April but stay in wet mud or shallow pools. They move onto drier areas by May after some growth (1.5-2.5 cm). There are up to 30 fish per 100 sq m on Kuwait mud flats. The activity range of body temperatures is 14-20°C in January and 26-34.5°C in June. Body temperatures do not exceed 35°C even when air temperatures exceed 40°C because of evaporative cooling. In tidal pools of a few centimetres depth in the Khawr az Zubayr, water temperatures ranged from 16 to 44ºC, pH from 7.6 to 8.7, dissolved oxygen from 5.2 to 8.8 mg/l and salinity from 10.2 to 20.2‰ (Al-Daham and Al-Noor, 2000). Holes from 50 to 80 cm depth, with two openings separated by not more than 50 cm, are constructed as refuge from extreme temperatures, high winds and predators. The mud is carried to the outside of the hole in the fish's mouth, and forms a dam-like structure around the shelter not exceeding 8 cm in height. The fish spends most of the ebb tide outside the shelter.

As well as being found on mudflats of the sea shore, this mudskipper is found in the Shatt al Arab and other rivers of the Persian Gulf.

Age and growth

Barak et al. (1994) studied this species in the Khawr az Zubayr, Iraq and found growth to be allometric with the regression coefficient significantly (p<0.05) greater than 3. (W = 1.74x10^-4 L^2.35 (r = 0.99)). Al-Daham and Al-Noor (2000) found the smallest mature males were 7.3 cm and females 7.4 cm in the Khawr az Zubayr with maturity at age one year. Sarafraz et al. (2011) found fish from Bandar-Pol and Qeshm Island had von Bertalanffy parameters L_∞= 141.51 mm, k = 0.46 year^-1 and t₀ = 0.79 year and L_∞= 166.79 mm, k = 0.42 year^-1 and t₀ = 0.62 year, respectively. Overall, males grew larger than females (208 mm versus 147 mm) while females grew faster (k = 0.41 versus 0.19 year^-1). The age when the theoretical length was 0 (t₀) was 1.46 year for males and 0.88 for females. Maximum age was estimated to be 4+ years.

Food

Fiddler crabs are stalked as the main prey of this mudskipper in Kuwait (Tytler and Vaughan, 1983) but shrimps and other invertebrates are also taken. High wind speeds and surface temperatures below 15ºC inhibited hunting. Hunts were spatially well separated because of the long time period before crabs returned to the surface after a hunt in their vicinity (Clayton and Snowden, 2000). On the intertidal mudflats of Iraq at the head of the  Persian Gulf, this mudskipper feeds predominately on fish when larger than 90 mm (frequency 78.9%, occurrence 80.0%) with shrimps (14.1%, 20.0%), insects (3.2%, 10.0%), copepods 2.1%, 5.0%) and Daphnia sp. (1.7%, 5.0%). Fish smaller than 80 mm had values much lower for fish (6.7%, 8.3%) and higher for copepods (75.1%, 83.3%) with Daphnia sp. at 13.3% and 16.6%, insects at 2.7% and 4.1% and shrimps at 2.2% and 4.1%. Barak et al. (1994) found this species to be cannibalistic and piscivorous in the Khawr az Zubayr based on gill raker gap, gut-length/body length ratios decreasing with size, and stomach contents. Copepods were the major food item of smaller mudskippers (<70 mm) while mudskippers larger than this took fish. Mhaisen and Al-Maliki (1996) report food items as percentage of occurrence from fish caught in the Khawr az Zubayr estuary of Iraq to be 67.2% crustaceans (shrimps, crabs, barnacles and others), 34.5% snails, 3.4% insects and 1.7% fishes. Some fish consume plant material in winter months only, presumably in the absence of animal food.

Reproduction

Spawning in the marine environment of the Khawr az Zubayr takes place in March, the release of larvae being timed to take advantage of phytoplankton and zooplankton blooms (Hussain and Ahmed, 1999). Al-Daham and Al-Noor (2000) give the spawning period as March to April in the Khawr az Zubayr with a fecundity of 11,560-35,005 eggs for fish 7.4-12.9 cm long. A water temperature over 18ºC was the primary factor for spawning stimulation.

Parasites and predators

Mhaisen and Al-Maliki (1996) give information for Iraqi fish. E. Kahrom in the Crocodile Specialist Group Newsletter reports that muggers (marsh crocodile, Crocodylus palustris) eats a Periophthalmus in the Sarbaz River of Iranian Baluchestan (www.flmnh.ufl.edu/natsci/herpetology/newsletter/news173b.htm, downloaded 15 February 2002). However this may well be Boleophthalmus dussumieri.

Economic importance

None.

Conservation

No study of the numbers of this species in Iranian waters has been carried out so its status cannot be assessed.

Further work

The biology and population numbers of this species in Iran needs study.

Sources

The colour description is based on Kuronuma and Abe (1986).

Iranian material: None seen.

Comparative material: CMNFI 1985-0183, 2, 35.1-40.7 mm standard length, Iraq, Shatt al Arab (no other locality data); BM(NH) 1954.11.10:1-2, 2, 112.6-119.0 mm standard length, Iraq, Fao (29º58'N, 48º29'E); BM(NH) 1976.12.8:1-2, 76.1-84.1 mm standard length, Iraq, Basrah (30º30'N, 47"47'E); BM(NH) 1981.3.19:7-10, 4, 91.3-104.3 mm standard length, Kuwait mudflats (no other locality data).

Ponticola
Iljin, 1927

This genus contains 13 species in in the Black and Caspian Sea basins (Freyhof, 2011) with 4 species in Iranian waters. Species were formerly included in Neogobius but a molecular study by Neilsen and Stepien (2009a) separates them.

Ponticola cyrius
(Kessler, 1874)

Common names

gav mahi rud-e Kura (= Kura River goby) or gavmahi-ye Rud-e Kurosh.

[Kura goby, Kura River goby].

Systematics

Studies by Vasil'eva (1995a) and Vasil'yeva and Vasil'yev (1995) indicate that gobies from the upper and middle Kura River described as Gobius cyrius Kessler, 1874 and Gobius Weidemanni Kessler, 1874, and identified by various authors as Gobius platyrostris, Gobius constructor, Gobius platyrostris cyrius, Gobius cephalarges constructor, Neogobius cephalarges constructor and Neogobius platyrostris constructor should all be referred to Neogobius (now Ponticola) cyrius.

Gobius cyrius was described from the Kura River near Borzhom, Georgia and 3 syntypes are in the Zoological Institute, St. Petersburg under ZISP 2235 (Eschmeyer et al., 1996). One of these, a male 103 mm total length and 84 mm standard length, is designated as the lectotype by Vasil'yeva and Vasil'ev (1995). Two syntypes of Gobius Weidemanni described from Transcaucasia are under ZISP 2224.

Key characters

The pelvic fin anterior membrane has large, angular lateral lobes, at least one-fifth width of rear edge and pelvic fin less than nine-tenths distance to anal fin; the posterior nostril is near the edge of the orbit; lateral series scales usually 54-76; upper lip moderately swollen, width about 0.75 to more than length lateral preorbit; and interorbital distance 0.4-0.8 eye diameter.

Morphology

The head width is much greater than its depth. The interorbital distance is not more than half the eye diameter. The top of the head and the occiput are scaled with cycloid scales. The upper lip is expanded towards the mouth corners, sometimes narrowing at the very end. The lower jaw protrudes and the angle of the jaws reaches back below the anterior half of the eye. The snout is longer than the eye diameter (1.3-14 times). The upper lip is swollen at the angle. The second dorsal fin is of equal height along its length or rising slightly higher at its middle or end. The pelvic fin has a well-developed membrane with pointed lobes and does not extend to the anal opening. The caudal peduncle is compressed, depth about 0.30-0.35 length. The caudal fin is usually rounded but may be pointed, truncated or scalloped. The predorsal area is marbled and the first dorsal fin has a distal dark band.

First dorsal fin with 6-8, usually 6, spines, second dorsal fin with 1 spine and 15-20, usually 18-19, soft rays, and anal fin with 10-16, usually 14, soft rays (but see below), pectoral fin rays 17-19, and lateral line scales 53-78. Vertebrae 33-34. The chromosome number is 2n=36-42 (Klinkhardt et al., 1995).

Meristics in Iranian material: first dorsal fin spines 6(38), second dorsal fin with 15(7), 16(28) or 17(3) soft rays, anal fin with 10(1), 11(8), 12(26) or 13(3) soft rays, and pectoral fin rays 17(3), 18(28) or 19(7). Lateral line scales 54(2), 55(5), 56(7), 57(11), 58(6), or 59(4).

Diploid chromosome number 36-42, chromosome arms 46, polymorphism seen in a pair of subteleocentric chromosomes, the number of which varies from 0 to 2.

Sexual dimorphism

Males may not become black during the breeding season (Vasil'yeva and Vasil'yev, 1995). There are various differences in morphometric characters, summarised in Vasil'eva and Vasil'ev in Miller (2003).

Colour

The body is marked by a reticulate or marbled pattern in dark fawn, by scattered light spots and by 8-10 elongate dark spots along the lateral line. The back anterior to the dorsal fin is marbled. The belly is paler than the flank. The first dorsal fin is dark, particularly in the upper part where the darkening may form a band, with a transparent margin and a conspicuous black spot anteriorly below the tip of the fin. The first dorsal, caudal and anal fins have light margins but the fins are mostly dark. The light edge is obvious in the anterior parts of the first dorsal and anal fins. Only the second dorsal fin ray tips are light. The pectoral and pelvic fins are both uniformly dark.

Size

Attains 101.3 mm standard length, 13.0 cm total length.

Distribution

This species is found in the Caspian Sea basin including the Anzali Mordab and tributary rivers, the Massuleh River at Siahbar, and the Pasikhan River just above confluence with Pirbazar River and a tributary near Islamabad (Ahnelt and Holčík, 1996; Abdoli and Naderi, 2009) and the upper and Middle Kura River and upper Aras River of the former U.S.S.R. (Berg, 1948-1949; Vasil'eva and Vasil'ev in Miller, 2003).

Zoogeography

This species is distributed in rivers of the Caspian Sea basin in Azerbaijan and Iran while Neogobius constructor, with which it has been confused, is found in the Black Sea basin. The absence of P. cyrius from the lower Kura River could have been prevented by the prior penetration of P. gorlap according to Vasil'eva and Vasilev (1995).

Vasil'eva and Vasilev (1995; 1996a) consider that Sarmatian marine ancestors of modern P. cyrius and N. constructor most probably moved into fresh water during the Miocene, about 5 MYA. Mountain building in the Caucasus isolated the Kura and other rivers which once flowed to the Black Sea and their course became oriented to the Caspian Sea. Isolation of the gobies resulted in speciation.

Ahnelt and Holčík (1996) present an alternative view. They place the origin of this species in the Quaternary when fresh water from melting glaciers connected the Black and Caspian seas via the Manych Channel allowing freshwater fishes to disperse. This occurred four times during the Pleistocene, the last time about 14-12,000 years BP. A goby species was able to colonise both fresh and brackish water and particular stocks began to favour certain habitats. Those stocks which favoured headwaters evolved into P. cyrius while those which favoured lower regions and coastal areas evolved into P. gorlap. Ahnelt and Holčík (1996) point out that there is an analogous situation in the Black Sea with N. constructor and the species N. rhodioni Vasil'yeva and Vasil'yev, 1995. Additionally all west Caucasian and Caspian riverine gobies are very similar morphologically as evidenced by the difficulty in constructing reliable keys, suggestive of recent differentiation about 11,000-9,000 years BP after the isolation of the Black and Caspian seas.

Habitat

This small goby is found only in freshwater in mountain and foothill zones in contrast to P. gorlap. It is found in shallow (3 m or less) streams with a high gradient and current speed (1.6-4.9 m/sec on the bottom) in Iran (Ahnelt and Holčík, 1996). However, Vasil'yeva and Vasil'yev (1995) record it as absent in areas of strong current in the Kura River, preferring slow current and muddy bottoms. This type of habitat is limited in Iranian rivers which are much shorter and smaller than those of the Caucasus where an extensive lowland course is found. In Iran, the stream bed is composed of stones and boulders with some pebbles in the upper reaches and pebbles and gravel in the lower reaches. Small body size is an advantage for hiding under rocks to avoid predators and to escape the rapid current.

Age and growth

Life span is up to 3 years with maturity attained in the second or third year (Vasil'eva and Vasil'ev in Miller, 2003).

Food

Vasil'eva and Vasil'ev in Miller (2003) report feeding on insect larvae and parts of plants.

Reproduction

This species may contain eggs in three size groups, the largest being 2.81 mm in diameter, indicative of batch spawning. Total fecundity reached 1060 eggs. Spawning occurs from May to August at 11-20ºC, in some localities reported only for April-May (Vasil'eva and Vasil'ev in Miller, 2003).

Parasites and predators

Unknown.

Economic importance

None reported although in Azerbaijan some are caught by anglers.

Conservation

Further field work is necessary to assess numbers and status of this species.

Further work

The biology, distribution and conservation status of this species, recently recorded from Iran, remain to be examined in detail.

Sources

Counts and data are based on Ahnelt and Holčík (1996).

Ponticola goebelii
(Kessler, 1874)

Common names

gavmahi-ye ratan, gel-ye mahi ratan. ?name cahnge

[Kaspiiskii bychok-rotan or Caspian ratan or rotan goby in Russian].

Systematics

The Caspian Sea basin subspecies was usually referred to Neogobius ratan goebelii (Kessler, 1874). Gobius Goebelii Kessler, 1874 was described from Baku, Azerbaijan and Gobius ratan was originally described from Odessa on the Black Sea.

Gobius Bogdanowi Kessler, 1874 described from the Caspian Sea at Makhachkala (Petrovsk) is a synonym (the male of N. ratan goebeli according to Iljin (1956) although Pinchuk (1991) and Ragimov (1998a) consider it to be a subspecies of N. ratan). Pinchuk (1976) notes that fish from the Azerbaijan and Iranian coast differ from those from Dagestan and Turkmenistan, the first having fewer scales, but the number of specimens were insufficient to define taxa.

Gobius Goebelii has a syntype in the Naturhistorisches Museum Wien under NMW 33910 and others possibly in the Zoological Institute, St. Petersburg (ZISP 2229-30) (Eschmeyer et al., 1996; Pinchuk et al., 2003). Two probable syntypes of Gobius ratan are in the Muséum national d'Histoire naturelle, Paris under MNHN A.1125 and a syntype is in the Zoologisches Museum Berlin (Museum für Naturkunde, Universität Humboldt, Berlin) under ZMB 2098 (Bauchot et al., 1991). Two syntypes of Gobius Bogdanowi are possibly in the Zoological Institute, St. Petersburg (ZISP 10902) (Eschmeyer et al., 1996; Pinchuk et al., 2003).

Key characters

Pelvic fin anterior membrane with angular lateral lobes, not more than one-fifth width of rear edge; pelvic fin almost reaches the anal fin (0.9 distance) or extends beyond the anal fin origin; posterior nostril near edge of orbit; anterior nape with cycloid scales; rear of first dorsal fin without a dark spot; lateral series scales usually 49-54; and upper lip width 0.4-0.67 lateral preorbital width (lip to orbit).

Morphology

Pelvic fin anterior membrane with angular lateral lobes, rather than rounded; lobes small, not more than 0.2 width of rear edge; posterior nostril near edge of orbit; angle of jaw below pupil of eye; upper lip slightly swollen posteriorly, 0.5-0.67 lateral preorbital area (between lip and eye); first dorsal fin with sub-horizontal upper profile; rear of first dorsal fin without a dark spot; head depth at eyes slightly less to somewhat greater than width between upper origins of opercles; snout length about 0.9-1.2 orbit; lateral series scales usually 52-61; interorbital width 0.4-0.6 eye diameter; nape scales cycloid; pelvic fin almost reaches the anal fin (0.9 distance) or extends beyond the anal fin origin; the caudal peduncle depth almost equals its length, the posterior nostril is close to the eye margin, and colour dark brown with few spots (spawning males black). The two subspecies listed above are distinguished partly by scale counts, 63-66 in bogdanowi and 63 or less in goebeli.

First dorsal fin with 5-7, usually 6, spines, second dorsal fin with 1 spine and 15-19 soft rays, anal fin with 1 spine and 11-15 soft rays, and pectoral rays 17-21. Range in lateral series scales 49-70. Vertebrae 32-34.

Sexual dimorphism

Male colouration is distinctive and they have a higher dorsal fin.

Colour

Overall colour is dark brown with a few, discrete, rounded pale spots and, along the mid-flank, a series of small horizontal bars. Pale saddles cross the back. The first dorsal fin has a yellow or intense orange margin above a black bar (white in preserved fish). This fin also has a dark blotch, often with a bluish tint, on the first and second and second and third interradial membranes, and sometime son the third and fourth interradial membrane. The second dorsal fin is greyish with 3-4 rows of brown spots proximally, and it may have a pale margin. The pectoral and caudal fins have rows of rusty-brown spots proximally. The pelvic fin disc and the anal fin are grey with a broad pale margin. The belly is grey. Breeding males become black with a bluish tint.

Size

Reaches 23 cm.

Distribution

Found in the Black and Caspian seas including Iranian waters of the latter.

Zoogeography

See genus account above.

Habitat

This species lives in inshore waters over rocks, gravel and stones, although a spawning male was caught over silt near the Kura River, and a female was caught at 11 m at Krasnovodsk (Pinchuk et al. in Miller, 2003). It rarely enters fresh waters, at least in the Caspian.

Age and growth

Sexual maturity is attained at 2 years.

Food

The main food items are crustaceans, with smaller quantities of worms, molluscs and fish.

Reproduction

Spawning takes place from the end of March to the end of May, with a single repeat spawning. Eggs are deposited on and between stones. Females contain 22-360 ripened eggs (Pinchuk et al. in Miller, 2003).

Parasites and predators

None reported from Iran.

Economic importance

None as it is disliked by commercial and sport fishermen and is not common in the Caspian Sea (Pinchuk et al. in Miller, 2003).

Conservation

No data for Iran. Endangered in Turkey (Fricke et al., 2007).

Further work

The biology of this species in Iranian waters requires study.

Sources

Iranian material:

Ponticola gorlap
(Iljin, 1949)

Common names

mahi kafzi (= bottom-dwelling or benthic fish), gel-ye mahi sar bozorg (= bighead goby), gavmahi-ye sarbozorg, gav mahi sar gondeh, sebele, gorzak.

[Names once used for Neogobius kessleri gorlap may be applied to this species: iribogaz xul for Azerbaijan; bychok-golovach or bighead goby in Russian; gorlap goby, Caspian bighead goby]

Systematics

The Caspian Sea basin was thought to contain the subspecies Neogobius (now Ponticola) kessleri gorlap (Iljin, 1949). Iljin (1956) and Vasil'yeva (1991) considered P. k. gorlap to be a distinct species while Berg (1948-1949) and Pinchuk (1977) on external morphological grounds considered it to be a subspecies. Karyotype data (Vasil'ev and Grigoryan, 1993) shows P. k. kessleri from the Black Sea basin to have 29 chromosomes in males and 30 in females and the number of biarmed chromosomes in 2n=29 individuals is 17 and in 2n=30 individuals it is 16. Nominal P. k. gorlap from the Caspian Sea have 2n=46 in both sexes (Vasil'yev and Vasil'yeva, 1992). Vasil'ev and Grigoryan (1993), Vasil'yev and Vasil'yeva (1992), Vasil'yeva et al. (1994) and Vasil'yeva and Vasil'yev (1994) referred the Caspian Sea basin populations to Neogobius gorlap, but indicated that this taxon required redescription and this was carried out in 1996. Vasil'eva and Vasil'ev (1996) consider that Gobius gorlap Iljin is unpublished and nonvalid, i.e. a nomen nudum (Iljin's 1941 manuscript is lost) and give the taxon the name Neogobius iljini with a type locality in the Mangyshlak region of the Caspian Sea (holotype in the Zoological Museum of Moscow State University under ZMMGU P-19726 with paratypes ZMMGU P-46453 (3 specimens); note that the Zoological Museum of Moscow University (ZMMU; their acronym) has P-19726 and P-4643 (sic)(Pavlinov and Borissenko, 2001)). Kottelat (1997) points out that Berg (1948-1949; volume 3 including gobies dated 1949) had access to and used some of Iljin's data, thus making the name gorlap available. Indeed, any of the subsequent papers by Vasil'eva and Vasil'ev and others using the name with descriptive details would have made the name available. Neogobius iljini is therefore a junior synonym of Ponticola gorlap (Iljin in Berg, 1949). There is no type series for P. gorlap as it is based on Iljin's data as outlined above.

Key characters

Pelvic fin anterior membrane with angular lateral lobes, lobes about one-sixth to almost one-half width of anterior edge of membrane; pelvic fin less than nine-tenths distance to anal fin; posterior nostril near edge of orbit; anterior nape with ctenoid or cycloid scales; rear of first dorsal fin without a dark spot; lateral series scales usually 54-76; lateral lobes of pelvic fin anterior membrane large, at least one-fifth width of rear edge; upper lip not markedly swollen, width at least 0.6 lateral preorbital width (lip to orbit), if less than 0.75, then nape scales ctenoid; interorbital distance 0.8-0.9 eye diameter; and caudal peduncle depth 0.67-0.75 length.

Morphology

This species is separated from other Caspian gobies in Iran by having a completely scaled nape, scales usually cycloid on the sinciput (anteriorly on the head just behind the eyes) (70-100% cycloid; 0-30% uniseriate ctenoid in Kura River fish) and cycloid or ctenoid posteriorly over the operculum (60-100% ctenoid in Kura River fish, 0-50% ctenoid in others); scales on the middle of the upper third of the operculum usually cycloid (70-100%); head depth at the eyes is slightly less or about equal to head width between the upper origins of the opercles; a large mouth with the jaw angle below the anterior part of the eye; the snout is much longer than the eye, 1.5-1.6 times; upper lip not expanded, or only slightly, less than lateral preorbital area (between lip and eye); interorbital distance less than 0.85 eye diameter; first dorsal fin not higher than second dorsal fin; moderately large, angular or pointed rather than rounded lateral lobes to the anterior pelvic membrane (rather small and obtuse lobes according to Ahnelt and Holčík (1996)), the membrane is 0.2-0.3 the width of the rear edge as opposed to not more than one-sixth; pelvic disc length is about 0.8 length of pelvic origin to anus length; scales in lateral series 53-79; caudal peduncle depth is 0.6-0.75 its length; the posterior nostril is close to the eye margin; and overall colour is yellowish and marbled.

The head in fish from the Kura River and possibly Iran have a rather subcylindrical shape (43.8-60.0%), while marine and north and middle Caspian Sea basin fish have a depressed and wide head, the width being markedly greater than the depth. The caudal fin is rounded, oval, or rarely elongated.

First dorsal fin spines 5-7, usually 6, second dorsal fin with 1 spine followed by 15-20, usually 18, soft rays, anal fin with 1 spine and 11-16, usually 13-15 (but see below), soft rays, pectoral fin rays 17-22, and pelvic fin rays 8-9. Marine specimens and those from the lower Volga River and Yashan Lake in the Uzboi River system of Turkmenistan have less than 15 anal fin branched rays while freshwater populations (in the Kura River at least, perhaps Iran) have 30-60% of all fish with 15 rays. Scale counts in the southern Caspian Sea are less (53-74) on average than for other populations (61-79) (Vasil'eva and Vasil'ev, 1996). Gill rakers 5-8. Vertebrae 33-35. The chromosome number for P. gorlap is distinctive with 2n=46 with 46 chromosomal arms (Vasil'ev and Grigoryan, 1993; Esmaily and Kalbassi, 2008).

Meristic values for Iranian specimens are: first dorsal fin spines 6(16), second dorsal fin soft rays 16(4), 17(11) or 18(1), anal fin soft rays 12(13) or 13(3), pectoral fin rays 18(8) or 19(8) and lateral line scales 63(5), 64(2), 65(2), 66(2), 67(2) or 68(2).

Sexual dimorphism

Abdurakhmanov (1962) reports on fish from Azerbaijan that head width, predorsal distance, second dorsal fin and anal fin bases and length of third branched anal fin ray are all greater in males while pelvic fin length and eye diameter are greater in females. In sea populations, females are larger than males.

Colour

A strongly yellow to reddish-yellow coloration distinguishes this species (Berg, 1948-1949; Vasil'eva and Vasil'ev, 1996) although Gavlena (1977) describes Volgograd Reservoir specimens as brown and others agree fish may be dark brown to dark grey or greenish. There are 4-8 elongated dark brown spots along the mid-flank in freshwater specimens, the last forming a horizontal "T" with the cross-bar on the caudal fin base. The flanks are usually marbled dark brown with light brown and yellowish strips, sometimes in a cellular design. There are light spots, darkly rimmed, along the sides of the head and near the pectoral fin bases, the latter also being likened to a network, reticulate pattern or cellular design. Cheeks with reticulate or roundish-cellular design. Short, longitudinal stripes often present below the eyes. The belly is light grey or light yellowish.

Dorsal, caudal and pectoral fins yellowish to light brownish. Second dorsal fin branched ray tips white. The fins typically have rows of small dark, orange-grey spots, although the pelvic fin has only a little dark grey or yellowish pigment with some brownish strips or many minute spots. The first dorsal fin lacks a large spot but has 3-4 series of spots; the second dorsal fin has 2-6, usually 3-4, series of spots; the anal fin is yellow to grey with occasional spots; the pectoral fin has 8-10 series of spots; and the caudal fin has 7-8 series of spots. The ends of the second dorsal fin branched rays are white. The anal fin has a light border as does the pelvic disc, although the latter sometimes has a black centre. The caudal fin has many minute spots. The genital papilla is dark grey. Young fish may appear spotted but have a more reticulate pattern on the flank than N. goebelii and are generally darker.

The dorsal fins in breeding males have a wide yellowish or white margin and the second dorsal fin rays have free tips. The margin is rusty in a female. The head can be a dark bluish-grey and the flanks are dark with some paler markings. Fin membranes become dark.

Size

Reaches 22.5 cm. Freshwater populations have fish much smaller than those in the sea (Vasil'eva and Vasil'ev in Miller, 2003).

Distribution

Found in the inshore Caspian Sea and tributary rivers. It is reported from between Kultuk and Astara in Azerbaijan (Ragimov, 1965) and from the Uzboi Lakes in Turkmenistan. In Iran, it is reported from a wide range of rivers from Astara to the Gorgan and probably the Atrak, including the Siazan, Safid, Duyusan, Shimrud, Khoshkerud, Palarud, Naviq, Shasdehrud, Shafarud, Kargan, Gharasu, Tajan, Babol, Haraz, Pol-e Rud and Safid, the Aras River, the Anzali Mordab and Bahambar, Siah Darvishan, Pasikhan, Massouleh and Pir Bazar river, Gorgan Bay, the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea (Holčík and Oláh, 1992; Ahnelt and Holčík, 1996; Abbasi et al., 1999; Kiabi et al., 1999; Abdoli and Naderi, 2009). Abdoli and Naderi (2009) consider it to be absent from the Atrak, Sardab, Tonekabon and Aras rivers.

Zoogeography

This species is thought to have evolved from populations which settled in the lower reaches of rivers and in coastal areas while those populations which penetrated headwaters evolved into P. cyrius (q.v.) (Ahnelt and Holčík, 1996). See also genus account above.

Habitat

This species is found in fresh and brackish waters in rivers and lagoons and in inshore waters of the Caspian Sea. In the sea, it is found down to 10 m, rarely to 20 m, on rocky and dense sand bottoms. It moves inshore in the sea for spawning and retreats to deeper water (6-12 m) to overwinter (Vasil'eva and Vasil'ev in Miller, 2003). It may be found among reeds. It can live at river sites with a current velocity at 4.5 m/sec on the bottom (Holčík and Oláh, 1992). This species is allopatrically distributed with Ponticola cyrius (q.v.). Ahnelt and Holčík (1996) rate this species as a eurytope, inhabiting both fresh and brackish waters, slow and rapid currents, and clay and pebble and gravel bottoms. Kirilenko and Shemonaev (2010) found fish in the Kuibyshev Reservoir in Russia to prefer rocky, sandy-slimy grounds rich in higher aquatic vegetation and are sometimes found among cane roots.

Age and growth

Brackish water populations grow larger than freshwater ones (Ahnelt and Holčík, 1996). Males attain 3 years, females 2 years, and males grow faster than females. Maturity is reached at 1+ for most females and 2+ years for males (Vasil'eva and Vasil'ev in Miller, 2003). Kirilenko and Shemonaev (2010) found a female in the Kuibyshev Reservoir that was 4 years old while the oldest fish in the 3+ class were all males, fish matured at 1+ years for both sexes. Abdoli et al. (2006) examined fish from the Gomishan and Miankaleh wetlands and found a length (L)-weight (W) relationship of W = 0.1L^2.39 for males, 0.0595L^2.588 for females and 0.1L^2.4 for sexes combined.

Food

The principal food in the sea is fishes, mostly gobies and Atherina, but also includes crustaceans. Benthic food means this species competes with commercial fishes. In fresh water, fishes eaten include Nemacheilidae and the cyprinid Alburnoides bipunctatus (= eichwaldii), as well as crustaceans such as gammarids (e.g. Dikerogammarus haemobaphes), gobies such as its own species and N. melanostomus, insects and clams (Gavlena, 1977). Kirilenko and Shemonaev (2010) found food in the Kuibyshev Reservoir to be mainly  crustaceans and chironomids.

Reproduction

Spawning takes place in June in the Volgograd Reservoir and each female may contain up to 576 eggs (Gavlena, 1977). In the Caspian Sea, fish have as many as 3506 large eggs and 3399 smaller ones. Spawning takes place on rock and shingle bottoms with eggs laid on various objects. The males of this species are nest guarders. Spawning in the southern Caspian is in April and May with two batches of eggs deposited. In the lower Volga River, spawning is from the end of April to July (Vavsil'eva and Vasil'ev in Miller, 2003).

Parasites and predators

The Caspian seal, Pusa caspica, is a predator on this species (Krylov, 1984). Pazooki and Aghlmandi (1998) found the nematode Dichelyne minutus infecting the intestine of 100% of fish examined from the south Caspian Sea in Iran. and Sattari et al. (2002; 2004) and Sattari (2004) record the presence of the nematode, Eustrongylides excisus, in this species. This parasite can damage muscles in commercial species and render them unsuitable for sale. Dichelyne minutus was also recorded. Daghigh Roohi and Sattari (2004) record Eustrongylides excisus, Dichelyne minutus and Corynosoma strumosum from this species in the southwestern Caspian Sea of Iran. Sattari et al. (2005) surveyed this species in the inshore area of the Caspian Sea, recording Eustrongyloides excisus and Dichelyne minutus.

Economic importance

None in Iran although it has formed a small part of the goby catches in the former Soviet Union. It is also caught by anglers (Vasil'eva and Vasil'ev in Miller, 2003).

Conservation

Kiabi et al. (1999) consider this species to be of least concern in the south Caspian Sea basin according to IUCN criteria. Criteria include abundant in numbers, widespread range (75% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin.

Further work

The biology of this specie sin Iran needs work.

Sources

Meristics and colour description based in part on Gavlena (1977) describing fish from the Volgograd Reservoir, identified as N. kessleri. Counts and data for Iranian fish are based on Ahnelt and Holčík (1996).

Iranian material:

Ponticola syrman
(Nordmann, 1840)

Common names

None (other than general names listed under genus above).

[shirman in the Ukraine, syrman goby, Kaspiiskii shirman or Caspian syrman goby]

Systematics

Gobius syrman is described from Odessa, Dniester estuary, in the former U.S.S.R., now Ukraine). Gobius Trautvetteri Kessler, 1859 described from the lower Bug and Dniester rivers in the former U.S.S.R. and Gobius eurystomus Kessler, 1877 described from the southern Caspian Sea are synonyms. Berg (1948-1949) has eurystomus as a valid subspecies of Neogobius syrman but this is not accepted now (Reshetnikov et al., 1997). Presumed syntypes of G. syrman are in the Natural History Museum, London (BM(NH) 1872.5.30:35, 105.0 mm standard length), Muséum national d'Histoire naturelle, Paris (MNHN A. 1126) and in the Naturhistorisches Museum Wien (MNMW 30099. Syntypes of G. eurystomus are under BM(NH) 1897.7.5.8-9 (2, 73.6-88.6 mm standard length), in the Zoological Institute, St. Petersburg (ZISP 10904-05), and perhaps NMW 29176. (Pinchuk et al. in Miller, 2003).

Key characters

Three transverse suborbital neuromasts rows occur ventral to the longitudinal suborbital row b while all other Neogobius have typically two rows. Additionally, pelvic fin anterior membrane with rounded and shallow lateral lobes, lobes not more than one-sixth width of anterior edge of membrane, or lacking entirely; pelvic fin disc two-thirds distance to anal fin origin; nape with ctenoid scales; first dorsal fin without large dark spot; lateral series scales usually 55-70; and angle of jaw below pupil of eye.

Morphology

First dorsal fin with 5-7, usually 6, spines, second dorsal fin with 1 spine and 15-19, usually16-18 soft rays, anal fin with 1 spine and 10-15, usually 12-14, soft rays, and pectoral rays 17-21. Range in lateral series scales 56-79. Vertebrae 34-35. Pelvic fin anterior membrane with very shallow, rounded lateral lobes. Posterior nostril near edge of orbit. Angle of jaw below anterior part of pupil, upper lip with uniform width, about half lateral preorbital area (between lip and eye). First dorsal fin relatively high, with rounded upper profile, without an upper anterior dark blotch. Second dorsal fin highest in middle. Head depth at eyes 1.1-1.2 width between upper origins of opercles. Interorbital width less than or equal to eye diameter. Snout length 1.3-1.4 orbit. Lateral series scales usually 59-67. Nape and predorsal area scaled completely. Breast, base of pectoral fin and upper part of opercle scaled, cycloid scales on ventral part of abdomen, opercle and anterior part of nape. Pelvic fin about two-thirds distance to anal fin origin. Caudal peduncle depth about half length. Posterior nostril close to the eye margin. The head canals and the free neuromasts on the body are typically arranged for a neogobiine. Three transverse suborbital neuromasts rows occur ventral to the longitudinal suborbital row b.

Sexual dimorphism

Males may have a more intensely dark distal band and body spots during spawning. Male median fin rays are slightly elongated during spawning. Females are usually smaller than males.

Colour

Overall colour pale grey, brownish-grey or more rarely yellowish-brown (perhaps fish parasitised with the strigeid nematode Neascus), with pale saddles across the back extending onto the flank and sometimes meeting dark blotches along the mid-flank. The body has large grey-brown markings arranged in a chequer-like pattern. The head has brown markings laterally and a dark band antero-ventrally from the eye to the upper lip. The first dorsal fin has a pale yellowish margin set off by a dark stripe above two brown stripes proximally. The second dorsal fin bands are less distinct and the anal fin has an indistinct, bluish band and a white margin. The pectoral fins are yellowish and the pelvic disc is pale. Belly pale. Males do not become dark during spawning (Pinchuk et al. in Miller, 2003).

Size

Attains 29.2 cm.

Distribution

Black and Caspian Sea basins including the Imeni Kirova or Kyzylagach Bay near the northwestern Iranian border (Kuliev, 1989) and between Kultuk and Astara in Azerbaijan (Ragimov, 1965) and recently recorded from Iran (Ahnelt et al., 2007). Reported from the Anzali Mordab and Gomishan Lagoon, Gorgan Bay, and the southwestern, southeastern and south-central Caspian Sea (Jolodar and Abdoli, 2004; Abdoli and Naderi, 2009). Introduced to the Aral Sea.

Zoogeography

See genus account above.

Habitat

This goby is found principally in the sea, with one report from fresh water in the Caspian Sea basin (Emba River, Kazakhstan). It is unusual in being found on mud and silt bottoms and can tolerate low oxygen concentrations (to 20% saturation). It is rare offshore at 6-20 m in the Caspian Sea. It is found in the Caspian at 1-10 m, retreating in summer to slightly deeper water, reappearing as autumn cooling occurs, and then spending the winter at 30-50 m. It approaches shores earlier than other gobies for spawning, as early as the latter half of February for males with females in the second half of March (Pinchuk et al. in Miller, 2003).

Age and growth

Maximum age may be 6 years although most fish probably live only half this time. Maturity may be attained shortly before age 1 year and by 2 years for most fish. Abdoli et al. (2006) examined fish from the Gomishan and Miankaleh wetlands and found a length (L)-weight (W) relationship of W = 0.0033L^3.41 for males, 0.0033L^3.5 for females and 0.003L^3.5 for sexes combined.

Food

Fish, crustaceans and Nereis worms are the main diet items in Caspian Sea fish examined. Fish included Knipowitschia and fry of Neogobius pallasi and N. melanostomus as well as clupeids and its own species. Smaller individuals take crustaceans and larger ones favour fish (Pinchuk et al. in Miller, 2003).

Reproduction

The spawning season is from the beginning of April into May in the southern Caspian Sea. The eggs are found in two sizes, indicative of batch spawning. Up to 8474 ripe eggs are found in each female. Eggs are 4.2 by 1.9 mm and are laid under and between stones, on any available object or even muddy bottoms.

Parasites and predators

This species is eaten by Sander lucioperca and fry are eaten by sturgeons.

Economic importance

This species has been fished in former Soviet waters of the Caspian Sea because of its large size but the proportion in catches varies from 1-50%. It is important as food for commercial species.

Conservation

Only recently recorded from Iran, its conservation status in unknown.

Further work

The distribution and abundance of this species in Iranian waters needs to be surveyed as it is an important food for commercial fishes.

Sources

Pinchuk et al. in Miller (2003) is a recent summary of data on this species.

Iranian material: CMNFI 1970-0544, 1, 141.7 mm standard length, Gilan, near Bandar-e Anzali, (37°28’N, 49°27’E); CMNFI 1979-0689, 9, 87.1-124.0 mm standard length, Gilan, Safid River at Hasan Kiadeh (37°24’N, 49°58’E); CMNFI 1970-0586, 1, 100.1 mm, Mazandaran, Gorgan Mordab at Ashuradeh-ye Kuchak (36°50’N, 53°56’E); NMW 95074, 2, 100.1–130.2 mm, Mazandaran, south-east Caspian Sea near estuary of Gorgan River (36°59’N, 53°59’E); CMNFI 1979-0788, 2, 135.3–146.2 mm standard length, Mazandaran, Gorgan River (37°00’N, 54°07’E); NMW 95075, 1, 186.6 mm standard length, Mazandaran, south-east Caspian Sea, Mian Kaleh near Behshahr (36°53’N, 53°32’E).

Genus Proterorhinus
Smitt, 1900

This genus is characterised by having 6 first dorsal fin rays, a pelvic disc without obvious lateral lobes and, uniquely in Ponto-Caspian gobies, a very elongate anterior nostril which hangs over the lip. Miller in Miller (2004) give additional characters, in particular the distribution of neuromasts on the head. It contains only a single species found in the Black and Caspian seas and their tributary rivers and in the northern Aegean Sea in Greek fresh waters. There may be two species if P. semilunaris is recognised (see below). Simonovič (1999) considered this genus to be a subgenus of Neogobius but Ahnelt and Duchkowitsch (2001) provisionally consider Proterorhinus to be distinct based on their study of the lateral line system and consider it distinct based on osteology (Ahnelt and Duchkowitsch, 2004). Miller in Miller (2004) recognises the genus as distinct as do Stepien and Tumeo (2000) based on mtDNA. Simonovič et al. (1996) consider this genus of gobies to be a young one as evidenced by the distribution of the species in the Caspian Sea which closed recently.

Reshetnikov et al. (1997) and Miller in Miller (2004) have the date for this genus as 1899 but Eschmeyer's "Catalog of Fishes" states that it was published in 1900 although dated 1899.

Proterorhinus nasalis
(De Filippi, 1863)

Common names

gav mahi, sag mahi, gel-ye mahi marmari, gavmahi-ye marmari, sebele.

[marmar xul in Azerbaijan; bychok-tsutsik or tubenose goby, marmornyi bychok or marbled goby, both in Russian; mottled goby].

Systematics

The Caspian Sea tubenose goby has generally been referred to Proterorhinus marmoratus (Pallas, 18l4). Gobius marmoratus was originally described from Sevastopol, Ukraine, on the Black Sea. Types are lost (Miller in Miller, 2004). Gobius nasalis De Filippi, 1863 described in Latin from the "Mar Caspio presso Baku" and Gobius blennioides Kessler, 1877 described from "Bakinskoi bukhte" (= Baku Bay), were regarded as synonyms. The meristic characters reported by De Filippi (1863) for nasalis are probably in error according to Berg (1948-1949) but the only character falling outside the ranges compiled below is for soft dorsal rays given as 21.

Stepien and Tumeo (2006) used mtDNA cytochrome b sequence data and consider there are two species in this genus. P. marmoratus is a marine species in the Black Sea and P. semilunaris (Heckel, 1837) is a freshwater species in other Eurasian habitats. The type locality of the latter is "Maritza [Marizza] R., near Plovdiv, e. Rumelia, Balkan region of Bulgaria". Caspian Sea basin Proterorhinus were not investigated. Kottelat and Freyhof (2007), Freyhof and Naseka (2007) and Sorokin et al. (2011) restrict marmoratus to brackish waters in Sevastopol and consider nasalis to be the name for Iranian Caspian Sea populations.

Neilson and Stepien (2009b) examined mtDNA and nuclear DNA and confirmed the presence of a distinct taxon in the Caspian Sea basin. They advocated P. semipellucidus as the name for the Caspian Sea basin taxon. Gobius semipellucidus Kessler, 1877 was described from a single specimen taken at the "ust'e rechki Kara-su, vpadayushchei vb Astrabadskii zalivb" (= mouth of the Karasu River falling into Astrabad Bay (Qareh Su, Gorgan Bay) and the holotype is in the Zoological Institute, St. Petersburg (ZISP) (Eschmeyer et al., 1996). P. semipellucidus is given as a valid species in Eschmeyer's "Catalog of Fishes" but is presumably a synonym of P. nasalis. The relationship between marine Caspian Sea (brackish) populations (nasalis) and true freshwater populations (possibly semipellucidus) remains to be resolved. Neilson and Stepien (2009b) examined only freshwater and brackish (0-6 p.p.t.) specimens from the Caspian Sea basin. Sorokin et al. (2011) consider nasalis to be the taxon widely distributed in the Caspian and Sea of Azov basins with pellucidus a synonym, although further work is needed to determine if pellucidus is the freshwater taxon.

The syntypes of Gobius nasalis are in the Istituto e Museo di Zoologia della R. Università di Torino under MZUT N.672 (7 specimens), the Natural History Museum, London under BM(NH) 1869.3.4:34 (1, 43.4 mm standard length), in the Museo Civico di Storia Naturale di Genova under MSNG 12655 (2) and MSNG 36228 (3), in the Naturhistorisches Museum Wien under NMW 33894 (1), NMW 33895 (1) and NMW 33896 (1), and in the Museum für Naturkunde, Universität Humboldt, Berlin under ZMB 5015 (3) (Eschmeyer et al., 1996; Miller in Miller, 2004; 43.3-48.4 mm standard length, measured in February 2006). The holotype of Gobius semipellucidus is lost. Ahnelt and Mikschi (2008) give details on the types of Gobius semilunaris.

Key characters

The combination of the pelvic fins forming a disc, the head not being flattened, and the anterior nostrils forming a tube overhanging the upper lip are distinctive. The origin of the first dorsal fin is displaced anteriorly in comparison to other Ponto-Caspian and Atlantic-Mediterranean gobioids, and this reflects the differing postcranial osteology detailed in Ahnelt and Duchkowitsch (2004).

Morphology

First dorsal fin spines 5-7, usually 6, second dorsal fin with 1 spine and 12-20, usually 16-17, soft rays, anal fin with 1-2 spines and 11-17, usually 13-14, soft rays, and pectoral fin with 14-16 branched rays. Scales in lateral series 34-53. Scales are a vertical oval with the anterior margin rounded to slightly wavy, the upper and lower margins rounded and the posterior margin with almost straight upper and lower elements coming almost to a central point. This causes the exposed portion of the scales to be delimited by almost straight edges and flank scales have a diamond pattern. Circuli are numerous and fine. Radii are numerous and radiate back from a focus almost at the posterior margin. The posterior scale margin bears fine ctenii. Gill rakers 3-6, short and concentrated around the angle of the gill arch. A membrane partly closes off and narrows the gill opening at the gill raker level and may partially encompass a raker making counts difficult. Vertebrae 30-33. The chromosome number is 2n=46, with 46 acrocentric chromosomes and 46 chromosomal arms (Ráb, 1985; Grigoryan and Vasil'ev, 1993; Simonovič, 1999). The predorsal area on the back and the nape are scaled. The cheek has infraorbital neuromast organs in 7 transverse rows from the lower orbit border without uniserial papillae between the rows. The preopercular canal has three pores, the anterior oculoscapular canal has 7 pores and the posterior oculoscapular canal has 2 pores. Ahnelt and Duchkowitsch (2001) give a detailed description of the lateral line system on the head. The gut is short and s-shaped. The genital papilla has a two-lobed tip.

Freyhof and Naseka (2007) note that Caspian tubenose gobies are most similar to P. semilunaris (Heckel, 1837) of the Aegean and Black seas basins and are distinguished by having a shorter posterior membrane to the first dorsal fin, not reaching the origin of the second dorsal fin (versus reaching), a longer anterior naris reaching to the middle or to the lower margin of the lower lip when folded down (versus to the upper lip or to the upppermost margin of the lower lip), and a smaller eye (diameter 16-21% head length versus 20-28%).

Meristic values for Iranian specimens are:- first dorsal fin spines 5(1), 6(28) or 7(1); second dorsal fin soft rays 13(1), 14(6), 15(17) or 16(6); anal fin soft rays 12(13), 13(14), 14(2) or 15(1); total pectoral fin rays 14(18) or 15(12); lateral series scales 36(1), 38(4), 39(7), 40(7), 41(4), 42(5), or 44(2); total gill rakers 3(18), 4(9) or 5(3), although accuracy is doubtful because of the membrane; and total vertebrae 31(12) or 32(13) (courtesy of Nina Bogutskaya, January 2012).

Sexual dimorphism

Males are overall darker than females, e.g. one at 60.1 mm standard length had pigment on both rays and membranes of fins, and all fin margins frilly and pale or orange-yellow. Cheeks are swollen in spawning males and fins are longer than in females.

Colour

Overall colour is brownish or yellowish-brown to olive or yellowish-green with about 5 oblique and irregular bars or blotches across the flank. Colour varies with the background, being darker on mud bottoms and a bright reddish-brown on sand. The head has brown-grey bands over the top and sides on a pale background. The first dorsal fin may have a pinkish tinge and irregular grey blotches. The second dorsal fin has several series of brown spots with the upper 2-3 greenish-yellow. The caudal fin is grey interrupted by up to 9 narrow bands of greenish-yellow. There is a triangular black spot at the caudal fin base, flanked by two white spots. The pectoral fin is similarly greyish with 5-7 narrow bands of pale green or yellow. The pelvic fin has 3-4 yellow bands and the anal fin 6-7 yellowish and oblique bands over a grey background. The iris has a narrow golden ring. Spawning males have all fins dark, although the pectoral fin is lighter than the rest and the caudal fin has an obvious white margin. The genital papilla is grey. Breeding females have a colour similar to that of both sexes in winter. Young (16-22 mm) have an unpigmented median band, wider than the eye, from the head to the first dorsal fin and even to the caudal fin. In front of the first dorsal fin is a dark saddle. The peritoneum is light brown to silvery with varying amounts of melanophores.

Size

Attains 15.0 cm although Caspian specimens reputedly reach only 7.6 cm.

Distribution

Found in the Caspian Sea basin and the Uzboi Valley of Turkmenistan. It is found in a wide range of rivers on the Caspian coast of Iran including the Qareh Su falling into Gorgan Bay, Kargan River estuary near Hashtpar, lower Safid,  Rud-e Sera and Babol, in the Anzali Mordab and Kolesar River, the southeast Caspian Sea, the southwest Caspian Sea and south-central Caspian Sea (Derzhavin, 1934; Holčík and Oláh, 1992; Abbasi et al., 1999; Kiabi et al., 1999; Abdoli and Naderi, 2009).

Zoogeography

The genus Proterorhinus diverged from the related genus Neogobius about 5.2MYA during the late Miocene/early Pliocene according to mitochondrial DNA evidence (Dillon and Stepien, 2001). Freshwater and marine/brackish populations apparently diverged 3.82-4.30 MYA and freshwater lineages in the Black and Caspian seas diverged 0.92-1.03 MYA (Neilson and Stepien, 2009b).

Habitat

This species occurs in both salt and brackish waters and enters the fresh water of rivers. There are some permanent freshwater populations in Europe. The usual habitat is shallow sea bays, offshore banks or flowing water of streams but it may also be found in ponds and canals overgrown with vegetation. Where current is strong it hides under boulders. Some fish are found below 3 m depths in the sea. It is often found under stones or among weed, to which it can retreat rapidly if disturbed. Most activity takes place at night.

Age and growth

Life span is variably reported as 2 or about 5 years with maturity attained at 1-3 years. Young-of-the-year can mature by autumn at 5.5 cm in the Caspian Sea (Miller in Miller, 2004).

Food

Kuliev (1989) records insect remains, gammarids, daphnia, chironomids, molluscs and fish eggs in the guts of this species in Kirova Bay of Azerbaijan. For the Caspian Sea as a whole, amphipods predominate at 45.7% followed by mysids at 21.8%, cumaceans at 16.4% and decapods at 7.2%. Molluscs make up 5.6% (Kosarev and Yablonskaya, 1994). Iranian specimens contained crustacean and insect remains. Elsewhere polychaete worms and small fish have been found in stomachs of this species (Miller in Miller, 2004).

Reproduction

Both sexes produce sounds during the breeding season. Eggs are laid from shallow water (0.5 m) down to 20 m in bowl-shaped nests, under rocks, in empty mollusc shells, and on roots and stems of plants. Empty cans may be used. Two females may lay eggs in the same nest. Spawning begins in mid-April in the southern Caspian and may continue as late as the first half of August. Some fish may be mature in the middle of March in Iranian waters. Fish presumed to be young-of-the-year at 9.8 mm standard length have been collected on 26 April, by 10-11 June fish are 11.2-11.6 mm (mean 11.4 mm), on 20 June the 5 smallest fish of a sample were 12.5-14.1 mm, mean 13.6 mm while the 5 largest were 21.0-25.2 mm, mean 23.4 mm, and on 12 October the 5 smallest were 16.6-19.9 mm, mean 17.7 mm while the 5 largest were 26.4-33.3 mm, mean 29.6 mm. By 15 March, eggs in a 49.7 mm standard length fish are 1.3 mm in diameter and well-developed. This data suggests an extended spawning season in Iran. However young are first found in mid-June according to Ragimov (1987). Eggs are deposited in 2-3 batches and are guarded. Females contain up to 1335 eggs of diameter 3.3-3.6 by 1.4-1.5 mm. Elsewhere up to 2500 eggs may be laid. Egg clutches can be transported on the hulls of ships (Ahnelt et al., 1998). Males are nest guarders.

Parasites and predators

Unknown for Iran.

Economic importance

Robins et al. (1991) list this species as important to North Americans. Importance is based on its use in aquaria and because it has been introduced outside its natural range (Jude, 2001).

Conservation

Lelek (1987) classifies this species as vulnerable in Europe on account of water level changes. Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include few in numbers, medium range (25-75% of water bodies), absent in other water bodies in Iran, and present outside the Caspian Sea basin.

Further work

The biology of this species in Iran is not well known.

Sources

Type material: See above for Gobius nasalis (ZMB 5015).

Iranian material: CMNFI 1970-0530, 66, 41.6-64.5 mm standard length, Gilan, Nahang Roga River (37º28'N, 49º28'E); CMNFI 1970-0542, 5, 48.0-59.6 mm standard length, Gilan, Old Safid River estuary (37º23'N, 50º11'E); CMNFI 1970-0585, 2, 52.6-55.9 mm standard length, Gilan, Nahang Roga River (37º28'N, 49º28'E); CMNFI 1970-0590, 5, 39.5-47.7 mm standard length, Mazandaran, Shesh Deh River near Babol Sar (no other locality data); CMNFI 1979-0787, 3, 52.7-59.1 mm standard length, Gilan, Nahang Roga River (37º28'N, 49º28'E).

Genus Rhinogobius
Gill, 1859

Members of this genus are characterised by an elongate body which is compressed posteriorly, a depressed head, a long snout, usually small scales on the occiput, short soft dorsal and anal fins both with 9-10 rays, the first dorsal fin with 6 spines, scales are ctenoid and number 23-40 in lateral series, anterior nostrils are tubular, the tongue is not notched, and teeth are simple.

There are about 48 species in Japan, Korea, Taiwan, China and the Amur River basin of eastern Asia. One species, presumably from the Amur River basin in the former Soviet Union, has been introduced to Turkmenistan and has reached Iranian waters.

Rhinogobius similis
Gill, 1859

Common names

gel-ye mahi, gavmahi-ye talabi (= pond or lake goby).

[lake goby]

Systematics

Rhinogobius similis was originally described from Shimoda, Japan

Rhinogobius similis lindbergi Berg, 1933 described from the Amur and Ussuri rivers, Russia is the subspecies of the Amur River basin according to Pinchuk (1978) but Eschmeyer (1998) records it as a synonym of the type subspecies. The Iranian specimens probably had their ultimate origin in the Amur River basin. Vasil'eva (2007) and Vasil'eva and Kuga (2008) consider that the Rhinogobius introduced to Central Asia are R. cheni (Nichols, 1931), a Chinese species of the Yangtze River, and this could be the species found in Iran. However, the large number of species in the genus, the poor state of knowledge on these fishes and the source presumably being the Amur River, leaves this identification as open.

Key characters

The only member of its genus in Iran, its key characters are those outlined in the genus.

Morphology

Dorsal fin spines 5-8, dorsal soft rays 7-10 after an initial unbranched ray, anal fin soft rays 6-10 after an initial unbranched ray, lateral series scales 28-36. Scales can be absent from the midline of the nape and the parietal and occiptal regions but this is variable (the nominal subspecies lindbergi lacks scales). Adult fish have the dorsal spines elongated (but not in lindbergi, not even in males). Scales in small Iranian specimens are a vertical oval, the posterior margin is fringed with ctenii, circuli in these small specimens are moderately devloped, radii radiate from the central point of the posterior margin to the anterior margin, the posterior margin has almost straight upper and lower margins coming to a central point so flank scales form a diamond pattern. The gut is a short s-shape. Gill rakers number 8-12 and are short and touch the adjacent one when appressed. Total vertebrae number 24-28.

Meristic values for Iranian specimens are:- first dorsal fin spines 6(3); second dorsal fin soft rays 9(3); pectoral fin rays 18(2) or 19(1); lateral series scales 31(3); total gill rakers 10(1) or 11(2); and total vertebrae 27(2).

Sexual dimorphism

Unknown.

Colour

Overall colour is a pale yellow or light brown with 6 brownish blotches on the flank and 6 blotches on the back, their position alternating. A dark band runs through the eye to the posterior edge of the mouth. The upper head is speckled brown. The belly is white. There is a dark spot between the first and second dorsal fin spines in the nominal lindbergi subspecies. There are 2 rows of spots on the first dorsal fin and 3-4 more distinctive rows on the second dorsal fin. The caudal fin has 2-5 rows of spots. The anal fin bears pigment distally on the membranes. The pectoral and pelvic fins are greyish. The pigmentation of the type subspecies is given by Pinchuk (1974) but may differ in detail from the nominal lindbergi subspecies so is not given here.

Young fish have 6 blotches along the mid-flank and membranes of fins are either strongly pigmented overall or bear up to 6 bars on the first dorsal fin, second dorsal fin and caudal fin with pectoral, pelvic and anal fins much lighter, almost immaculate. There is a small blotch between the first and second first dorsal fin rays near the fin base. The distal margin of the anal fin is yellowish-orange. The peritoneum is silvery but has a strong development of melanophores dorsally.

Size

Attains 100 mm.

Distribution

Aliev et al. (1988) refer to an exotic species of goby occurring in the Tedzhen River of Turkmenistan in the text of their work but not in the table of distributions. A goby is also reported by Shakirova and Sukhanova (1994) and Sal'nikov (1995) from the Karakum Canal and the Kopetdag Reservoir in Turkmenistan on the northern borders of Iran. Specimens have been collected from Sarakhs, Iran in the Tedzhen (= Hari) River (Coad and Abdoli, 2000a; Abdoli et al., 2000) and Abdoli (2000) records it from the Kashaf and Hari rivers in the Tedzhen River basin.

Zoogeography

An exotic or alien species from eastern Asia, introduced to Turkmenistan from where it presumably entered Iranian waters. The genus Rhinogobius is in need of revision and the correct name for the taxon in Iran may change.

Habitat

The Iranian specimens were caught in the Hari River which had a depth of 35-120 cm , a width of 12-27 m, a turbidity reading of 15 cm, a water temperature of 12°C and a coarse gravel bed. It eastern Asia it is found in both rivers and lakes (hence the common name of lake goby as used in Japan). It is found on shallow sandy bottoms and on the upper surface of large stones in shallow water. Water temperatures reach 28°C (Kopylets and Dukravets, 1981).

Age and growth

Life span exceeds 4 years (Kopylets and Dukravets, 1981).

Food

Unknown.

Reproduction

Egg production reaches 1862 eggs in total (Kopylets and Dukravets, 1981).

Parasites and predators

Unknown for Iran.

Economic importance

Welcomme in Courtenay and Stauffer (1984) reports this species to be a pest when introduced.

Conservation

As an introduced species this fish requires no conservation.

Further work

The spread of this species in Iranian waters and its effects on native fauna should be documented.

Sources

Iranian material: Uncatalogued material, 5, 42.4-47.6 mm standard length, Khorasan, Hari River near Sarakhs (36º30'N, 61º10'E).

Channidae

This family is known as the snakeheads or serpent-heads because of the characteristic broad head with large scales and a large oblique mouth. They are found from Africa to eastern Siberia and Southeast Asia and comprise about 2 genera with 32 species (Eschmeyer and Fong, 2011) but the family is need of a revision. Maximum size is about 1.2 m.

Snakeheads are characterised by paired accessory organs or suprabranchial organs in the upper gill chamber (above and behind the gills) which enable these fishes to breathe air, survive low oxygen conditions and even reputedly travel overland; an elongate rounded body becoming compressed posteriorly; the dorsal and anal fins are long and of even height, and spineless; pelvic fins are present or absent; the mouth is large and the lower jaw protrudes; there are teeth on the jaws, vomer and palatines; gill openings are wide and the gill membranes are united but free from the isthmus; branchiostegal rays number 5; the caudal fin is rounded; scales are small and cycloid or ctenoid; and colour is highly variable, rapidly changing to suit the surroundings.

Snakeheads are ambush predators, living in still waters although some inhabit the larger rivers. Most species build a bubble nest in vegetation, laying and fertilising the eggs below it so that they float up into the bubbles. Others are mouth brooders. One or both adults guard the nest and young and will attack intruders savagely, including humans according to folklore. Many species are known to aestivate in summer when the habitat dries. They can be carried alive wrapped in wet cloths or vegetation and may be introduced into areas outside their natural distribution.

A number of species grow large enough to be an important food in Southeast Asia but are also pests, eating more valuable species. Some species are popular in the aquarium trade. Juveniles may be called, incorrectly, "larvae" in the aquarium trade and are brighter in colour than adults.

Genus Channa
Scopoli, 1777

Channa Scopoli, 1777 has priority over Ophicephalus Bloch, 1793 (Eschmeyer, 1990). Ophiocephalus is an incorrect emendation. See also Myers and Shapovalov (1931-1932), DeWitt (1960), Ettrich and Schmidt (1989) and Pethiyagoda (1991) for discussions on the taxonomy of this genus and species.

The characters listed under the family above obtain for the genus which has only one confirmed Iranian species.

Channa argus
(Cantor, 1842)

Reported as Channa argus warpachowskii (Berg, 1909) from the Karakum Canal and Kopetdag Reservoir in Turkmenistan as an exotic from China (Shakirova and Sukhanova, 1994; Sal'nikov, 1995). This canal connects with the Tedzhen River basin shared with Iran and ultimately may connect with the Caspian Sea basin. No Iranian record.

Channa gachua
(Hamilton, 1822)

Common names

mahi-ye sarmari (= snakeheaded fish).

[tond, dolli or dauli in Pakistan; dwarf snakehead, frog snakehead, brown snakehead, oriental snakehead, smooth-breasted snakehead].

Systematics

Ophicephalus gachua was originally described from Bengal, India. Possible syntypes are in the Natural History Museum, London under BM(NH) 1858.8.15.54 (1) and BM(NH) 1858.8.15.144 (1) (Eschmeyer's "Catalog of Fishes", downloaded 29 August 2007).

Key characters

The large head scales and elongate dorsal and anal fins are distinctive.

Morphology

Dorsal fin rays 30-37 (the last 2 rays counted as 1 where close together at base), anal fin rays 20-24, pectoral rays 13-16, and lateral line scales 39-47. Pelvic fins may be present or absent. The lateral line is displaced down one row under, or just beyond, the posterior end of the pectoral fin. Scales have a vertical anterior margin, parallel dorsal and ventral margins and a rounded posterior margin. The anterior dorsal and ventral corners are square cut, rounded to sharp. Circuli are fine and numerous on the anterior field but on the posterior field become coarser and are parallel to the horizontal axis. Radii are numerous in the anterior field and radiate from a central focus. Gill rakers are minute. The gut is short and s-shaped. The anterior nostril is tube-shaped and hangs over the upper lip to the mouth. The chromosome number is 2n=78 (Banerjee et al., 1988; Klinkhardt et al., 1995).

Meristic values for Iranian specimens are:- dorsal fin rays 33(1), 34(3) or 35(1) (the last 2 rays counted as 1 where close together at base); anal fin rays 22(5); pectoral rays 14(3), 15(1) or 16(1); and lateral line scales 41(2), 43(2) and 44(1).

Sexual dimorphism

Females have a dark eye-spot at the posterior part of the dorsal fin (Pethiyagoda, 1991).

Colour

Colour varies with the habitat. The back is usually greenish-grey to brownish with bluish tints and the flank is crossed by irregular oblique bars, less obvious in adults than young. The background colour of the flank is dove grey with a violet sheen in males. The dorsal, anal and caudal fins are slate-coloured and have characteristic, narrow and strong orange margins (white in preservative). The membranes of these fins may be an iridescent green. The dorsal fin may have a blue or bluish-green stripe with a vertical extent from the fin mid-point distally about half-way to the fin margin on the membranes. The caudal fin has blue and green rays. Females have a dark eye-spot at the end of the dorsal fin. The pectoral fin base is dark blue and there are 4-5 orange and blue bands on the fin, with the margin orange. Bars on the pectoral fin are very distinctive in preservative, alternating dark and light. The iris is reddish. The peritoneum is silvery.

Size

Attains 33 cm (Day, 1875-1878) although Courtenay and Williams (2004) give 17 cm, probably more accurate given taxonomic confusion in the past.

Distribution

Reported from the Dasht and Rakshan rivers, the Makran coast and the Mashkel (= Mashkid) River basin in Pakistan (Zugmayer, 1913). Iranian records were limited to 4 specimens collected by N. A. Zarudnyi in the Bampur river (upper or middle course) during 15-23 July 1898 (27 June-4 July in Berg (1949)) until 1 specimen was found in the Halil River basin near Sabzeveran at 28°39'N, 57°45'E, over 300 km northwest of the Bampur River at Bampur (Coad, 1979a). Abdoli (2000) reports this species from the Halil and questionably from the Iranian Makran. Ebrahimi (2001) maps two localities in the Halil River. The map in Berra (2001) has this species too close to the Straits of Hormuz and the map in Courtenay and Williams (2004) does not extend far enough into Iran.

Zoogeography

The distribution of this species in southeastern Iran is confirmed in Coad (1979a), a record not noted by Bănărescu (1992b). It is the westernmost occurrence of the species in Asia. It is found eastwards to Indonesia (Ettrich and Schmidt, 1989).

Habitat

This species can survive in turbid and poorly oxygenated water because of its ability to breathe air. Air breathing is so well developed that this snakehead can travel overland between water bodies, using a hopping motion. Two pharyngeal suprabranchial cavities extend along the body to the caudal peduncle and are lined with vascularized mucous membranes. Mountain streams, rivers, lakes, reservoirs, ponds, rice paddies and even hot springs are recorded as habitats for this species in South Asia. Clear water in shallow streams and swamps in forested areas are preferred (Courtenay and Willimas, 2004) while Pethiyagoda (1991) states that flowing water is preferred. It is found in mud among emergent vegetation in Sri Lanka (De Silva, 1991). It may be largely nocturnal. This species can survive temperatures as low as 13°C, a pH range of 3.1-9.6, brackish water, and waters low in calcium, low in mineral content and pronounced anion excess (Lee and Ng, 1994). Low temperatures may be a limiting factor in its distribution in Iran.

Age and growth

Some populations in mountain streams are mature at about 13 cm while in lower areas maturity is reached at about 10.2 cm at 20 months. The population examined in Sri Lanka has 90% of the individuals less than 24 months old and 99% less than 38 months. Longevity is about 6 years (De Silva, 1991).

Food

This species is recorded as a nocturnal predator on other fishes and on frogs but most diet studies indicate that insects and crustaceans are the main foods (De Silva, 1991; Pethiyagoda, 1991). Young fish feed on unfertilised eggs from the mother for about 4 weeks. These eggs are released and fall in the water (while those which hatch float). The young stimulate egg release through close body contact with the mother, who swims in a circle while releasing the eggs. In aquaria, a female will take Artemia nauplii into its mouth and swim over to the male which releases the young to feed on the nauplii as they are emitted from behind the gill cover (Ettrich and Schmidt, 1989). An Iranian specimen had only sand grains in its gut.

Reproduction

Spawning takes place over silt or gravel bottoms or in areas of cleared vegetation forming a "nest". Vegetation is cleared by fin movements and can be 15 cm across (Ettrich and Schmidt, 1989). Some reports have the female swimming belly up and the male then fertilises the eggs as they are released by swimming diagonally over the female's vent. Ettrich and Schmidt (1989) state that the male forms a loop around the belly region of the female, an intensive and long-lasting process. This occurs after pair-bonding lasting several weeks which serves to synchronise reproduction, necessary since all the eggs are released at once. The male picks up the eggs in his mouth and keeps them there for 4-5 days until hatching (Ettrich, 1989; Pethiyagoda, 1991), as the eggs are oily and slowly float to the surface. The fry may also be protected in the male's mouth for up to three days before releasing them, but retain the fry behind the gill cover when danger threatens or night descends (Ettrich and Schmidt, 1989). Egg numbers vary between 20 and 200 per spawning (Lee and Ng, 1994). Fecundity ranges from 389 and 7194 ((De Silva, 1991; Courtenay and Williams, 2004). Brood size (97-343 larvae) is smaller than the number of mature eggs reported for females according to De Silva (1991) and many eggs either fail to develop or are lost to predators despite parental care. An Iranian fish caught on 6 May contained small and possibly atretic eggs. Egg diameter is 2.6 mm and the eggs are a golden yellow.

Ettrich and Schmidt (1989) report that 6 days after being released from the mouth, the fry ascend to the water surface and draw air. A foam nest is produced under which the young fish hide.

De Silva (1991) found breeding to take place throughout the year in Sri Lanka, with enhanced breeding in May to July and October to December. In the Karnataka State, India this species breeds from May to August. Individuals appear to spawn once in each rainy season in Sri Lanka.

Parasites and predators

None reported from Iran.

Economic importance

This species is too rare in Iran to be of any economic importance but in Sri Lanka it consumes pests in rice paddies (De Silva, 1991) and in Singapore in 1990 sold for up to Singaporean $60 (Courtenay and Willimas, 2004).

Conservation

This species would be difficult to conserve in Iran as it is rare and at its extreme westernmost distribution. Survivability may be marginal and numbers low.

Further work

Surveys to determine the distribution of this species, its numbers and its environmental requirements may enable conservation to be effective.

Sources

Iranian material: ZISP 11714, 4, 42.9-70.2 mm standard length, Baluchestan, Bampur River (no other locality data); CMNFI 1979-0220, 1, 110.9 mm standard length, Kerman, irrigation ditch, 2 km south of Jiroft (= Sabzeveran) (28°39'N, 57°45'E).

Comparative material: BC 66-32, 2, 63.8-71.5 mm standard length, East Pakistan, Chittagong Hill Tracts, Karnaphuli Reservoir tributary (no other locality data); BC 66-38, 23, 79.5-124.9 mm standard length, East Pakistan, Dacca, Bellabor Fish Market (no other locality data); BC 66-44, 2, 109-6-122.3 mm standard length, East Pakistan, Tipperali, Chandpur (no other locality data).

Scophthalmidae

Genus Psetta
Swainson, 1839

Psetta maxima
(Linnaeus, 1758)

Introduced to the Soviet Caspian Sea basin as the subspecies Psetta maxima maeotica (Pallas, 1811) in 1930-1931 but not subsequently observed. The introduction probably failed because the pelagic eggs were not buoyant at the low Caspian salinities (Baltz, 1991). No Iranian record.

Pleuronectidae

Genus Platichthys
Girard, 1854

Platichthys flesus
(Linnaeus, 1758)

Introduced to the Soviet Caspian Sea basin in 1902 and 1930-1931 but not subsequently observed (Shukolyukov, 1937a). The introduction probably failed because the pelagic eggs were not buoyant at the low Caspian salinities (Baltz, 1991). Voronina (1999) is a recent systematic review of this species. No modern Iranian record although some were caught in the Anzali Mordab outlets in the 1930s (Holčík and Oláh, 1992). The Farsi name is pahn mahi.

© Brian W. Coad (www.briancoad.com)