Introduction

The freshwater fishes of Iran can be identified using these keys, aided by the Species Accounts. The keys should not be used for countries bordering Iran which share many species but also have others not found in Iran. All keys benefit from use and feed-back - please let me know if you encounter problems.

There are two sets of keys in this work. There is a general key to families (although all families are recognisable at a glance in Iran, with a little experience) and a series of keys to genera and species. Genera keys and species keys may be separate if there are many genera and species, or combined in a single key if there are few.

Identification keys are based on couplets, a choice between two alternatives, e.g.

1a. Mouth a large crescent; gill membranes joined to form a free fold over the isthmus = Huso huso
1b. Mouth small and transverse; gill membranes attached to isthmus---> 2

2a. Lower lip continuous, not split in middle; more than 48 lateral scutes, usually 55 or more; barbels fimbriate = Acipenser nudiventris
2b. Lower lip interrupted in the middle; less than 51 lateral scutes, usually less than 45 in Iran; barbels not fimbriate---> 3

If the fish has a large and crescentic mouth, then it is the fil mahi, Huso huso; if not, then the user is directed to the next couplet (2), and so on.

Ideally each couplet has a series of characters which reinforce each other and allow for any loss or damage to characters. Additionally, some characters are "key" but difficult to interpret without experience or are internal and require dissection which is not always possible. In some cases, only one character is available since it must encompass all included species below that point in the key. Since some species are difficult to identify, additional characters are given in brackets [.....]. These additional characters are not unique to the species but, in combination, help to identify the species. Definitions of characters are given in the Dictionary of Ichthyology.

If used properly, a key is more accurate and less time consuming than flicking through pages of text. The disadvantage of keys is that the alternative state in each couplet is not at hand if you only have one fish to examine, and a simple error can lead you widely astray. Some recognised species have overlapping counts for obvious meristic characters, although means and modes are significantly different, and differ in other, subtler ways not readily summarised in a key. Ideally a student of fishes should collect a series of individuals of different sizes and sexes from each locality, wherever conservation demands and practicality permits. A series of about 30-40 specimens allows for character variations dependent on sex and size, and on abnormalities, and also allows for comparative measurements and counts to be made. And more careful examination may reveal more than one species in the sample.

Distribution is often an important aid in assigning samples to a species. Readers should be aware however that fish farming in Iran has led to the translocation, either deliberately or by accident, of species into basins where they are not native. Distribution can appear as a key character when the species is found in basins exclusive of related species. In brackets [.....], distribution is not exclusive but can be an additional character as outlined above.

The most important characters for identification are the general body shape, the number, position and size of the fins, the position and size of the mouth, whether teeth are obvious or not, the number of scales along the flank and the number of rays in various fins, among others. Although colour is often a useful guide, it can also be misleading. Fish vary their colour to match their background or for spawning rituals. In general, it is best to use several characters to identify a fish rather than relying on a single one which can easily be misleading.

Large fishes can be examined for these characters using the naked eye, but various pieces of equipment are necessary for identification of smaller species or juveniles. Hand lenses are of some use in magnifying small characters but by far the best instrument is a binocular microscope which can magnify up to 50 times. Pharyngeal teeth, fin rays and scales can be counted with ease using a microscope. Attachments can be used to take photographs or project images of structures for drawing. Measurements can be taken under a microscope on small specimens to ensure accuracy, and a microscope leaves both hands free to handle the specimen and dissecting tools or calipers. Ichthyologists develop their own techniques for manipulating light sources and specimens for making structures readily visible. I prefer to have two light sources. One of these illuminates the surface of the fish for scale counts and observation of structures. The other bounces light off a white enamel tray into the microscope and is particularly useful for counting fin rays as the light travels through the fin enabling clear distinction of rays.

Two types of forceps are very useful. A large pair (25-35 cm long) enables specimens to be taken out of a jar and sorted without immersing one's fingers. Preservative solutions will irritate the skin and contact should be minimised; some ichthyologists wash the specimen in water before handling, but this may compromise subsequent effectiveness of preservatives. Fine plastic gloves can be worn, but some people develop allergies to latex. A very fine pair of forceps with needle-like points is used to spread folded fins to see the rays and to probe and examine other structures.

Scissors are necessary for slitting the belly and these will vary in size depending on the size of the fish. Fine scissors can be useful in dissection. Very large fish may require a sharp knife or scalpel for dissection or slitting the abdomen. The slit is usually made on the right side of the fish as the left side (head to left) is used for drawings and photographs.

A needle mounted on a wooden or metal handle can be used for cleaning gill arches of debris, clearing flesh from pharyngeal arches or lifting the edges of scales to help in counting them. Most commercial dissecting needles are too blunt and a fine needle can be taped on the end.

Measurements are best made with calipers for accuracy. Dial or electronic calipers are available which measure to an accuracy of 0.1 mm, and are available in several lengths. Very large calipers are usually vernier calipers, but an accuracy of 0.1 mm for large specimens is not required, or even attainable.

Examination of minute scales, debris encrusted gill arches or the lateral and cephalic line canals is facilitated by using compressed air delivered through a glass tube of 1 mm diameter. The air can come from a compressor or aquarium air pump, or even from a hand-squeezed bulb.
 

?pic

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Key to the Genera and Species of Cyprinidae

?check all genera are in this part of key

?tabulate main charctesr like spine, barbels, sucker?

The cyprinid family is the most speciose in Iranian fresh waters. Members of the family are more easily identified first to genus and then to species. Keys are then shorter and less liable to error in use. Additional characters can be listed under each genus or species which are not unique nor readily incorporated into keys but which in combination help to identify the genus or species. These additional characters are given in brackets. Monotypic genera key out to species in the generic key.

?Add petroleuciscus add Romanogobio, Luciobarbus, Carasobarbus, Kosswigobarbus, Mesoptamichthys, Tor, *Mylopharyngodon

1a. Branchiostegal membranes not attached to isthmus; gill rakers fused together; eyes low on side of head, below midline; suprabranchial organ present = *Hypophthalmichthys spp.

1b. Branchiostegal membranes attached to isthmus; gill rakers not fused; eyes at or above midline of head; suprabranchial organ absent ---> 2

2a. Serrated stiffened ray (spine-like) in the dorsal and anal fins; dorsal fin elongate (? rays or more, usually ?); anal fin origin below dorsal fin ---> 3 see iraq book
2b. No serrated stiffened ray (spine-like) in the anal fin; dorsal fin short to moderately elongate (?-? rays, usually ?); anal fin origin behind dorsal fin end ---> 4

3a. Barbels absent; pharyngeal teeth in one row = *Carassius

pic
3b. Barbels present (two pairs); pharyngeal teeth in three rows; ? and exotic = **Cyprinus carpio

4a. Eyes absent; body pink through lack of pigment; no scales = Iranocypris typhlops
4b. Eyes present; body pigmented; scales present, sometimes restricted to anal area ---> 5

mouth structure *Pseudorasbora parva peculiar short dorsal fin ray *Pimephales promelas other species to pull out here

Aspidoparia morar

Barilius mesopotamicus

*Ctenopharyngodon idella

*Hemiculter leucisculus

Leucaspius delineatus

*Pseudorasbora parva

**Rhodeus sericeus

Scardinius erythrophthalmus

5a. Anus and anal fin base sheathed by markedly enlarged scales ---> 6
5b. Anus and anal fin base not sheathed by markedly enlarged scales ---> 8

6a. Branched anal fin rays 5; scales mostly absent; pharyngeal teeth in two rows =  Schizopygopsis stoliczkai

6b. Branched anal fin rays 6; scales present; pharyngeal teeth in three rows =  

7a. Barbels absent or vestigial; anal fin branched rays 6; pharyngeal tooth formula 2,3,4-4,3,2 = Schizocypris altidorsalis

7b. Barbels present and well-developed; anal fin branched rays 5É see above; pharyngeal tooth formula 2,3,5-5,3,2 = Schizothorax spp.

8a. An adhesive disc prominent on the underside of the head = Garra

Underside of head of Garra persica

8b. No adhesive disc --->

9a. Scaleless keel extending from the throat to the anal fin; lateral line decurved and wavy = Pelecus cultratus
9b. Not as above ---> 10

10a. Barbels present ---> x
10b. Barbels absent ---> 11

11.  naked ventral keel Abramis  Alburnoides Alburnus  Blicca  Alburnus  Vimba  (also put alburnoides, alburnus in another couplet)

1. Barbels absent + spine in D D ray count [scales large, 29-35 in lateral line; body compressed; Tigris River basin; dorsal fin spine smooth, without denticulations] = Barbus sharpeyi

+ Mesoptamichthys? no barbels

x. Spine in dorsal fin ---> h
    No spine in dorsal fin ---> c

h. Spine smooth; mouth not sector-shaped  ---> j
    Spine with teeth; mouth sector-shaped (u-shaped in young) ---> i

j. Mouth with central tubercles Kosswigobarbus
Mouth without k

k Branched anal fin rays 6, dorsal fin branched rays 10 or more; lateral line scales ? = Cyprinion
   Branched anal fin rays 5; dorsal fin branched rays 9 or less; lateral line scales ? = Capoeta

j  = Carasobarbus luteus
= Tor grypus

c. Scales small, more than ?100 in lateral line = Tinca tinca
    Scales larger, less than ? in lateral line ---> q

q. Anal fin branched rays 13 or more = Barilius mesopotamicus
    Anal fin branched rays less than 13 ---> t

t. Dorsal fin branched rays 7; pharyngeal teeth in two rows = Gobio gobio
    Dorsal fin branched rays 8; pharyngeal teeth in one row ---> s

s. Lateral line complete = Crossocheilus latius
    Lateral line incomplete = Hemigrammocapoeta elegans

  Spine no barbel Acanthobrama marmid

  chck for more see above and Esmaeili list

Body and caudal peduncle compressed (caudal peduncle depth at anal fin insertion greater than caudal peduncle width); well-defined spots on the dorsal and caudal fins; Tedzhen River = Gobio gobio
Body only slightly compressed and the caudal peduncle cylindrical (caudal peduncle depth at anal fin insertion less than or about equal to caudal peduncle width); faint spots on the dorsal and caudal fins; Lake Orumiyeh and Caspian Sea = Gobio persus 

Key to the Species of Abramis

Both species are found only in the Caspian Sea basin.

1a. Branched anal fin rays 22-30 = Abramis brama

1b. Branched anal fin rays 31-44, mostly 34 or more = Abramis sapa

Key to the Species of Acanthalburnus

1a. Anal fin branched rays 13-19; lateral line scales 60-85; Caspian Sea basin = Acanthalburnus microlepis

1b. Anal fin branched rays 10-13; lateral line scales 50-68; Lake Orumiyeh basin = Acanthalburnus urmianus

Key to the Species of Alburnoides

Populations in the Esfahan and Tedzhen River basins are not yet identified to species.

1a. Snout pointed or slightly rounded; mouth terminal or upturned, tip of mouth cleft on level from slightly above middle of eye to upper margin of pupil; lower jaw slightly to moderately projecting relative to upper jaw; junction of lower jaw and quadrate on about vertical through anterior eye margin; Kor River basin = Alburnoides qanati
2b. Snout slightly to markedly rounded; mouth terminal to subterminal, tip of mouth cleft on level from middle of eye to below lower margin of eye; upper jaw slightly to moderately projecting relative to lower jaw; junction of lower jaw and quadrate on about vertical through about middle of eye ---> 2

2a. Branched anal fin rays 8-11, commonly 9-10; branched dorsal fin rays 7, rarely 8 ---> 3
2b. Branched anal fin rays 10-15, commonly 11-13; branched dorsal fin rays 8, rarely 7 ---> 4

3a. Ventral keel completely scaled; total vertebrae 40-41; abdominal vertebrae 20-22, commonly 21; Lake Orumiyeh basin = Alburnoides petrubanarescui
3b. Ventral keel scaleless from one-third to whole keel length; total vertebrae 38-40, commonly 39; abdominal vertebrae 19-20; Tigris River basin = Alburnoides nicolausi

4a. Ventral keel smoothed, scaled along one-third to whole length; Tigris River basin = Alburnoides idignensis
4b. Ventral keel well-pronounced, almost or completely scaleless ---> 5

6a. Lateral line in alive and preserved fish delineated by dark pigment dots above and below; 13-15 predorsal vertebrae; mouth terminal, tip of mouth cleft on or slightly below middle of eye; Caspian Sea basin = A. eichwaldii
6b. Lateral line in alive and preserved fish somewhat darker than surrounding flank but no strong dark dots outline to canal; 11-13 predorsal vertebrae; mouth almost subterminal, tip of mouth cleft on or below lower margin of eye; Namak Lake basin = Alburnoides namaki

Key to the Species of Alburnus

1a. Dorsal fin branched rays modally 7; strong mid-flank stripe [anal fin branched rays 9-13, usually 10-12; total gill rakers 12-17; lateral line scales 46-64, usually 50-60; Caspian Sea basin] = Alburnus filippii

1b. Dorsal fin branched rays modally 8; no strong stripe in Caspian Sea species ---> 2

2a. Total gill rakers 15-31, usually 19 or more [Caspian Sea basin] ---> 3
2a. Total gill rakers 10-18, usually 16 or less ---> 4

3a. Lateral line scales 54-74, usually 55 or more [anal fin branched rays 12-19; peritoneum light brown; Caspian Sea basin] = Alburnus chalcoides

3b. Lateral line scales 36-53, usually 48 or less [anal fin branched rays 10-21; peritoneum light silvery; Caspian Sea basin and translocated] = **Alburnus hohenackeri

4a. Lake Orumiyeh basin [anal fin branched rays 9-12, usually 10-11; total gill rakers 11-16; lateral line scales 46-63, usually 46-58] = Alburnus atropatenae

4b Tigris River and basins of southern Iran ---> 5

5a. Anal fin branched rays 9-10; upper Tigris River basin near ?; peritoneum silvery [total gill rakers 12-14; lateral line scales 67-83] = Alburnus zagrosensis

pic?
5b. Anal fin branched rays 10-18, usually 11 or more; elsewhere in southern Iran; peritoneum brown to black ---> 6

6a. Lateral line scales 43-58; anal fin branched rays 13-18, usually 14-16 [total gill rakers 10-13; Tigris River basin] = Alburnus caeruleus

6b. Lateral line scales 58-89, usually 60 or more; anal fin branched rays 10-14, usually 11-12 [total gill rakers 11-18; Esfahan, Gulf, Hormuz, Kor River, Lake Maharlu and Tigris River basins] = Alburnus mossulensis

Key to the Species of Aspius

The distinction of these two species has not been examined recently and characters overlap, sample sizes for gill rakers and scales in particular being very small. However, they are found in separate basins.

1a. Lateral line scales 62-105; anal fin branched rays 11-15, usually 12; total gill rakers 8-11; total vertebrae 50-51; Caspian Sea basin = Aspius aspius

1b. Lateral line scales 91-110; anal fin branched rays 10-13, usually 11?; total gill rakers 11-14; total vertebrae 51-53; Tigris River basin = Aspius vorax

Key to the Species of Capoeta

1a. Dorsal fin branched rays modally 7 [lateral line scales 42-62; total gill rakers 11-20; Bejestan, Dasht-e Kavir, Dasht-e Lut, Sistan and Tedzhen River basins] = Capoeta fusca

1b. Dorsal fin branched drays modally 8 or 9 ---> 2

2a. Dorsal fin spine strongly developed, longer than head [lateral line scales 68-90; total gill rakers 23-33; Gulf and Tigris River basins] = Capoeta trutta

2b. Dorsal fin spine well-developed to weak, not longer than head ---> 3

3a. Total gill rakers 9-17 [lateral line scales 72-99; dorsal fin spine weak and poorly serrated; Namak Lake basin] = Capoeta buhsei

3b. Total gill rakers 16 or more, usually 18 or more ---> 4

4a. Lateral line scales 36-52, mostly 39-48; [Dasht-e Kavir, Esfahan, Kerman-Na'in, Kor River, Namak Lake and Tigris River basins [total gill rakers 16-25] = Capoeta aculeata

4b. Lateral line scales 46-99; mostly 50 or more ---> 5

5a. Dorsal fin branched rays modally 9; often large black blotches on flank [lateral line scales 60-99; widespread] = Capoeta damascina

5b. Dorsal fin branched rays modally 8, sometimes 9; without black blotches ---> 6

6a. Irregular brown to black speckles on head and flank [lateral line scales 58-82; Gulf and Tigris River] = Capoeta barroisi

6b. Speckles absent; ?  [lateral line scales 46-70; widespread; Tedzhen River fish often with 4 barbels] = Capoeta capoeta

Key to the Species of *Carassius

Goldfish have been widely introduced in Iran; presence and distribution of other species is uncertain.

1a. Lateral line scales 25-34, mostly 31 or less; gill rakers 35-54, size dependent and mostly 39 or more in adults; anal fin branched rays modally 5; young never with dark spot on caudal peduncle = *Carassius auratus

1b. Lateral line scales 32-36; gill rakers 23-35, mostly 31 or less; anal fin branched rays modally 6; young usually with dark spot on caudal peduncle = *Carassius carassius

Key to the Species of Chondrostoma

1a. Caspian Sea basin [lateral line scales 50-68] = Chondrostoma cyri

1b. Outside Caspian Sea basin ---> 2

2a. Kor River basin [lateral line scales 49-57; dorsal fin branched rays usually 8] = Chondrostoma orientale

?pic
2b. Tigris River basin [lateral line scales 50-69; dorsal fin branched rays usually 8 or 9] = Chondrostoma regium

Key to the Species of Cyprinion ?

tabulate characters for comparison see berg?
 

1a. Mouth small with large lateral lobes; cartilage may form a tooth-like structure [dorsal fin branched rays 12-16; total gill rakers 10-15; Gulf and Tigris River basins] = Cyprinion kais

 
 

1b. Mouth without large lateral lobes; cartilage arched and not tooth-like ---> 2

Mouth in Cyprinion macrostomum

2a. Mouth oblique and long in lateral view [dorsal fin branched rays 10-13; total gill rakers 11-12; Hamun-e Jaz Murian, Hormuz and Makran basins] = Cyprinion milesi

2b. Mouth arched in young, transverse in adults ---> 3

3a. Dorsal fin branched rays 9-12, usually 10-11, means 10.0-10.5; southeastern and eastern Iran - Dasht-e Lut, Hamun-e Jaz Murian, Hamun-e Mashkid, Hormuz, Makran and Sistan basins = Cyprinion watsoni

 
3b. Dorsal fin branched rays 11-17, usually 12-15, means 13.1-13.9; southwestern Iran - Gulf, Lake Maharlu and Tigris River basins ---> 4

4a. Dorsal fin spine teeth well-developed, even near spine tip [Gulf and Tigris River basins] = Cyprinion macrostomum

4b. Dorsal fin spine teeth graded in size as near tip and finer [Gulf and Lake Maharlu basins]= Cyprinion tenuiradius

Key to the Species of Garra

?

1a. Caudal fin branched rays modally 16; ? (85.6% for 132 fish, range 15-17) [Hamun-e Jaz Murian, Hormuz and Makran basins] = Garra persica

1b. Caudal fin branched rays modally 17, 16 only rarely ---> 2

2a. Dorsal fin branched rays modally 8 (87.1% for 534 fish, range 6-8);  ? sucker structure [Gulf, Hormuz, Kor River, Lake Maharlu and Tigris River basins] = Garra rufa

rufa sucker pic? from Berg?
2b. Dorsal fin branched rays modally 7 (91.5% for 59 fish, range 6-8) ---> 3

3a. ?; eastern Iran (Bejestan, Hamun-e Jaz Murian, Hamun-e Mashkid, Dasht-e Lut, Makran, Sistan and Tedzhen River basins) = Garra rossica

3b. ?; western Iran (Tigris River basin) = Garra variabilis

Key to the Species of *Hypophthalmichthys

These two species are widely farmed.

1a. Abdomen with a compressed keel extending from the breast (pelvic fins) to the vent; pectoral fins short, not extending past the origin of the pelvic fins; gill rakers a continuous band uniting both sides, roots fused into a spongy mass = *Hypophthalmichthys molitrix

1b. Abdomen with a compressed keel extending from the throat to vent; pectoral fins long, extending past the origin of the pelvic fins; gill rakers free, no spongy mass = *Hypophthalmichthys nobilis

Key to the Species of Kosswigobarbus

1a. Lateral line scales 29-41; total vertebrae 39-40; Tigris River basin = Kosswigobarbus kosswigi

1b. Lateral line scales 24-27; total vertebrae 37-38; A'la River in Khuzestan and the Fahlian River in Fars = Kosswigobarbus sublimus

 Key to the Species of Luciobarbus ?

1a. Body covered with large dark spots arranged almost in a quincunx (pattern of five) [Tigris River basin] = Luciobarbus subquincunciatus

ph teeth? her and elsewhere
1b. Body without large spots ---> 2

2a. Head elongate, tapering and depressed anteriorly, pike-like, with postorbital distance in standard length 7.2 or less; adults very large, reputedly over 2 m long [Tigris River and Gulf basins] = Luciobarbus esocinus

2b. Head not as above; not very large, to ? m ---> 3

3a.Northern and northwestern distribution in the Caspian Sea, Lake Orumiyeh and Namak Lake basins ---> 4
3b.Southern and western distribution in the Gulf, Kor River and Tigris River basins ---> 6

4a. Dorsal fin branched rays modally 7 [predorsal length shorter than postdorsal length; lateral line scales 62-90, usually 65-77; total gill rakers 16-25; Caspian Sea basin] = Luciobarbus brachycephalus

4b. Dorsal fin branched rays modally 8 ---> 5

5a. Lateral line scales 51-72; without three lobes to lower lip; upper dark flank clearly delineated from lighter lower flank [predorsal length equal to longer than postdorsal length; total gill rakers 12-19; Caspian Sea basin] = Luciobarbus capito

5b. Lateral line scales 74-103, often 85 or more; lower lip usually with three lobes; body shades from dark to light gradually down flank [?predorsal length; total gill rakers 9-18; Caspian Sea, Lake Orumiyeh and Namak Lake basins] = Luciobarbus mursa

6a. Total gill rakers 7-13 [lateral line scales 57-68; Tigris River basin] = Luciobarbus xanthopterus

6b. Total gill rakers 14 or more ---> 7

7a. Lips markedly fleshy; fourth major row pharyngeal tooth large and molariform [scales?; Gulf, Kor River and Tigris River basins] = Luciobarbus barbulus

7b. Lips not markedly fleshy; ?Fourth major row pharyngeal tooth similar in size to third, not molariform?check [scales?]  ---> 8

8a. Dorsal fin spine strong, arising from an elevated base; dorsal fin origin at or ahead of pelvic fins origin [Gulf, Kor River and Tigris River basins] = Luciobarbus pectoralis

?better pic with stronger spine
8b. Dorsal fin spine present but not markedly strong; dorsal fin origin behind pelvic fins origin [Gulf and Tigris River basins] = Luciobarbus kersin

? pic needed with weaker spine and D further back - see Iraq book for key

Key to the species of Petroleuciscus 

1a. Dorsal fin branched rays 6-7, modally 7; anal fin branched rays 7-9, modally 8; total vertebrae 34-37; pharyngeal teeth 1.5-4.1; Gulf, Hormuz and Kor River  basins = Petroleuciscus persidis

1b. Dorsal fin branched rays 7-9, modally 8 or 9; anal fin branched rays 7-12, modally 9-11; total vertebrae 37-42; pharyngeal teeth usually 2.5-4.2 ---> 2

2a. Anal fin branched rays 9-12, modally 10 or 11; lateral line scales 45-56; total vertebrae 41-42; Esfahan basin = Petroleuciscus esfahani

pic?
2b. Anal fin branched rays 7-10, modally 9; lateral line scales 36-45; total vertebrae 37-38; Lake Orumiyeh basin = Petroleuciscus ulanus

Key to the Species of Romanogobio

Key by A. Naseka, Zoological Institute, St. Petersburg:- 

1a. Number of lateral line scales 41 to 45 with modes of 42 and 43; total vertebrae 38 to 42 with modes of 40 and 41; connection between the supraorbital and infraorbital head canals usually present; Caspian Sea basin = Romanogobio macropterus
1b. Number of lateral line scales 40 to 42 with modes of 40 or 41; total vertebrae 37 to 40 with modes of 38 and 39; connection between the supraorbital and infraorbital head canals usually absent; Lake Orumiyeh basin = Romanogobio persus

Key to the Species of Rutilus

These species occur only in the Caspian Sea basin.

1a. Lateral line scales 47-64, mostly 55-58; swimbladder elongate and conical or pointed posteriorly ---> 2
1b. Lateral line scales 39-48, mostly 42-47; swimbladder rounded posteriorly ---> 3

2a. = Rutilus frisii
2b. = Rutilus kutum

3a. = Rutilus caspicus
3b. = Rutilus rutilus

Key to the Species of Schizothorax ?

1a. Total gill rakers 24-41[lips thin; Sistan basin] = Schizothorax zarudnyi

1b. Total gill rakers 18 or less ---> 2

2a. lips?; Sistan basin = Schizothorax intermedius

2b. lips thick; Dasht-e Kavir and Tedzhen River basins = Schizothorax pelzami

Key to the Species of Squalius

1a. Flank scales outlined by pigment; anal fin rounded distally [Caspian Sea, Lake Orumiyeh, Namak Lake and Tigris River basins] = Squalius cephalus

1b. Flank scales not outlined by pigment; anal fin truncate or emarginate distally ---> 2

2a. Lower jaw not projecting; Tedzhen River basin = Squalius latus check on fish about lower jaw?

2b. Lower jaw projecting; Tigris River basin = Squalius lepidus

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Key to the Species of Cyprinodontidae

Almost any sample will contain both males and females, clearly distinguished by colour and pigment patterns.

?isfahanensis and check over key again

1a. Lateral line scales 36-47 [females finely speckled, no lozenge-shaped spot at caudal fin base; Tigris River basin] = Aphanius vladykovi

male  female

1b. Lateral line scales 24-35, mostly 31 or less ---> 2

2a. Total dorsal fin rays 4-7; total anal fin rays 6-10; gut variably coiled [Hormuz basin] = Aphanius ginaonis

male    ?gut pics

2b. Total dorsal fin rays 7-11, usually 9-10; total anal fin rays 8-12, usually 10-11; gut regularly coiled ---> 3

3a. Males lemon-yellow with two broad bars on caudal fin; females ? [Gulf, Hamun-e Jaz Murian, Hormuz, Makran and Tigris River basins] = Aphanius dispar

3b. Males not lemon-yellow; ?? ---> 4

4a. Males with blue spots on flank [Tigris River basin] = Aphanius mento

male

4b. Males without blue spots on flank ---> 5

5a. Females with flank bars [males barred]; Lake Maharlu basin = Aphanius persicus

malefemale
5b. Females with flank spots ---> 6

6a. ?Females without lozenge-shaped spot at caudal fin base; flank spots large; Tigris River basin =

malefemale

6b. Females with lozenge-shaped spot at caudal fin base; flank spots small; Kor River basin = Aphanius sophiae

malefemale
 

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Key to the Genera and Species of Gasterosteidae

1a.  Long dorsal fin spines, numbering 3; long pelvic fin spines, dorsal spines exceeding eye diameter in length; scutes (vertical bony plates on flank) large [Caspian Sea, Dasht-e Kavir and Tedzhen River basins] = *Gasterosteus aculeatus

1b.  Short dorsal fin spines, numbering 7-11, alternatively sloping left and right; dorsal spines shorter than eye diameter; scutes small [Caspian Sea basin] = Pungitius platygaster

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Key to Persian Gulf and Sea of Oman Drainage Species of the Gobiidae

1a. Lateral series scales large, 28-36; eyes not protruding = Glossogobius giuris

1b. Lateral series scales minute, over 90; eyes protruding above dorsal head profile ---> 2

2a. 4-5 first dorsal fin spines; anal fin base and second dorsal fin base 34% or more of standard length; 2 canine teeth internal to the lower jaw symphysis = Boleophthalmus dussumieri

2b.10-14 first dorsal fin spines; anal fin base and second dorsal fin base 27% or less of standard length; no canine teeth internal to the lower jaw symphysis  = Periophthalmus waltoni

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Key to Caspian Sea Genera and Species of the Gobiidae

? check against checklist for all species included eliminate species not definitely records

Some genera are monotypic or have only a single species in the Caspian Sea basin and so the keys terminates there. Speciose genera have separate keys below. The Iranian shore of the Caspian Sea remains poorly explored in its deeper waters and keys in Miller (2003), Mitrofanov (2003) and Boldyrev and Bogutskaya (2007) should be consulted for specimens which do not key out here (see also Species Accounts for further listings and discussion).

Note that a Rhinogobius species is recorded from the Tedzhen (= Hari) River basin in Iran as an exotic (see Species Accounts for description). This is the only goby outside the Caspian Sea basin and coastal waters of the Persian Gulf and Sea of Oman in Iran.

The following key is modified after Miller in Miller (2003):- ÉRECHECK!!

1a. Suborbital papillae with longitudinal row a immediately below eye and having at least one short side row; cheek with several short transverse rows, none reaching lower eye margin; snout with longitudinal rows s¹ and s² or, if transverse interorbital and snout rows, a perianal organ is present = Knipowitschia

e.g. Knipowitschia iljini

1b. Suborbital papillae in transverse rows; no row a; snout with transverse rows s¹ and s²; no perianal organ ---> 2

2a. Row 5i not below level of row 6i; 6i at or opposite end of row d; scales normal; canals present or absent ---> 3
2b. Row 5i below level of row 6i; 6i separated from posterior end of row d by row 5i; scales non-imbricate or bony tubercles and granules or naked; no canals ---> 7

3a. Anterior nostril an elongate tube hanging over lip = Proterorhinus nasalis

3b. Anterior nostril elongate but not overhanging lip ---> 4

4a. Three rows below row b = Mesogobius nonultimus

?pic
4b. Two rows below row b ---> 5

5a. Five rows before row b = Chasar bathybius

?pic

5b. Four rows before row b = 6

6a. = Neogobius
6b. = Ponticola

7a. No chin barbel or cheek flap; snout a duck-bill shape = Anatirostrum profundorum

 
7b. Chin barbel and cheek flap present; snout not a duck-bill shape = Benthophilus

The following key does not use papillae and head canal characters; see figures above. It is modified from Mitrofanov (2003) as translated courtesy of Dmitri Ponomarenko:- RECHECK

1a. Body naked ---> 2
1b. Body covered with regular ctenoid scales ---> 3

2a. Snout narrow and long = Anatirostrum profundorum
2b. Snout regular, not elongated ---> 3

3a. Anterior nostril elongated into a tube that hangs over lip ---> Proterorhinus nasalis
3b. Anterior nostril not as above---> 4

4a. Second dorsal fin short, with less than 12 branched rays; small fishes less than 50 mm ---> 5
4b. Second dorsal long, with more than 12 branched rays ---> 6 

5a. Scales on sides of body, with head, throat, belly and back to second dorsal fin scaleless; eyes lateral; body darkly pigmented without stripes; tail symmetrical without a dark spot at tail base ---> Knipowitschia caucasica
5b. Body fairly fully covered with scales; eyes pointed upwards; body with dark stripes; body glassy and translucent; tail symmetrical without a basal spot; deepwater species ---> Knipowitschia iljini

6a. Sinciput not covered with scales = Mesogobius nonultimus
6b. Sinciput and occiput covered with scales ---> 7

7a. = Neogobius
7b. = Ponticola

Key to the Species Benthophilus

The following key is modified after Pinchuk and Miller in Miller (2004). RECHECK See Boldyrev and Bogut too

1a. One or two dermal barbels behind jaw angle; first dorsal fin with 1-2 spines; tubercles large and high, not all spinous; tubercles in dorsal row 13-15, in ventral row 10-13 = Benthophilus baeri

1b. A dermal fold or lobe behind jaw angle (if absent, tubercles vertically elongated); first dorsal fin spines 3-4 (rarely 2); tubercles in dorsal row 18 or more, in ventral row14 or more ---> 2

2a. Tubercles vertically elongated, curved and crest-like, rear edges spinulose; temporal and occipital region without large tubercles; head narrow, interorbit with median groove between elevated ridges; dermal filaments present or absent; dermal fold behind jaw angle when present narrow, with an acute protuberance; back without brown bands ---> 3
2b. Tubercles conical and tipped by spines ---> 4

3a. Temporal and occipital region of head with granules; tubercles in dorsal row usually 30-33 = Benthophilus ctenolepidus

3b. Temporal region of head naked = Benthophilus pinchuki

?pic

4a. Tubercles distinct, relatively large; granules on temporal and occipital area small and sparse, or if slightly larger then not forming real tubercles; bands present = B. leobergius

4b. Tubercle rows distinct but tubercles relatively small; upper head and body densely covered with very small granules; no dark brown bands = B. macrocephalus

Key to Species of Knipowitschia

The following key is modified after Miller in Miller (2004).

1a. Males with 0-4 flank bars; anterior oculoscapular canals united at posterior interorbit, with a single median pore κ, and canals extending anteriorly to pores λ; preopercular canal present = K. caucasica

1b. Males with 6-10 flank bars; anterior oculoscapular canals more or less separate in midline of posterior interorbit, with pore κ double, and canals extending anteriorly through interorbit of variable extent, typically absent; preopercular canal present or absent = K. iljini

Key to the Species of Neogobius

The following key is modified after Miller and Vasil'eva in Miller (2003).

1a. Posterior nostril markedly distant from edge of orbit; pelvic fin anterior membrane with angular lateral lobes; lobes about one-sixth to almost one-half width of anterior edge of membrane  = N. caspius

1b. Posterior nostril near edge of orbit; 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 ---> 2

2a. At least anterior nape scales cycloid; first dorsal fin with large dark spot at rear; lateral series scales usually 49-55 = Neogobius melanostomus

2b. Nape scales ctenoid; first dorsal fin without large dark spot; lateral series scales usually 55-70 = Neogobius pallasi

Key to the Species of Ponticola

The following key is modified after Miller and Vasil'eva in Miller (2003). recheck?

1a. 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 = Ponticola syrman

pic?
1b. Pelvic fin anterior membrane with angular lateral lobes; lobes about one-sixth to almost one-half width of anterior edge of membrane ---> 2

2a. Lateral series scales usually 49-54; lateral lobes of pelvic fin anterior membrane small, not more than one-fifth width of rear edge; upper lip width 0.4-0.67
    lateral preorbital width (lip to orbit); nape scales cycloid; pelvic fin almost reaches the anal fin (0.9 distance) or extends beyond the anal fin
    origin = Ponticola goebelii

2b. Lateral series scales usually 54-76; lateral lobes of pelvic fin anterior membrane large, at least one-fifth width of rear edge; upper lip width at least 0.6
    lateral preorbital width (lip to orbit), if less than 0.75, then nape scales ctenoid; pelvic fin less than nine-tenths distance to anal fin ---> 3

3a. Upper lip not markedly swollen, width about 0.6-0.67 lateral preorbit; interorbital distance 0.8-0.9 eye diameter; caudal peduncle depth 0.67-0.75 length =
    Ponticola gorlap

3b. Upper lip moderately swollen, width about 0.75 to more than length lateral preorbit; interorbital distance 0.4-0.8 eye diameter; caudal peduncle depth  0.75
    to more than length = Ponticola cyrius

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Key to the Genera and Species of Mugilidae

?other species see Iraq book subviridis and vaigiensis; premaxilla pics

1a. Posterior end of maxilla not curved below tip of premaxilla, but straight; jaw end on line of gape; adipose eyelid well-developed, enclosing eye over much of anterior and posterior fields of iris, so pupil is covered by an oval slit; pyloric caeca 2; Marine, introduced to Caspian Sea = **Mugil cephalus

1b. Posterior end of maxilla curved below tip of premaxilla, visible behind corner of closed mouth; jaw end on below line of gape; adipose eyelid weakly-developed, not reaching pupil of eye; pyloric caeca 6-9 ---> 2

2a. Branched second dorsal fin rays 7; anal branched rays 8; pectoral fin long, reaching dorsal fin level; Gulf, Hormuz and Tigris River basins, translocated to Lake Maharlu basin = **Liza abu  check caeca?

2b. Branched second dorsal fin rays usually 9; anal fin branched rays 9; pectoral fin short, not reaching dorsal fin level; Caspian Sea basin ---> 3

3a. Pyloric caeca equal in length; scales of head and back with one groove; oral edge of preorbital moderately concave ---> *Liza aurata

3b. Pyloric caeca in two groups, 3-5 short and 3-4 long; scales of head and back with 2-7 or more grooves; oral edge of preorbital bone deeply notched = *Liza saliens

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Key to the Genera and Species of Nemacheilidae

1a.

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Key to the Genera and Species of Percidae

All naturally distributed in the Caspian Sea basin.

1a. Canine teeth absent; prominent bars on flank; anal fin branched rays usually 8-9, rarely 10; lateral line scales 77 or less = Perca fluviatilis

1b. Canine teeth present; no bars on flank; anal fin branched rays rarely 10, usually 11 or more; lateral line scales 78 or more ---> 2  

2a. More than 18 branched rays in the dorsal fin; interorbital width equal to or less than eye diameter [translocated] = **Sander lucioperca

2b. Less than 19 branched rays in the dorsal fin; interorbital width greater than eye diameter = Sander marinus

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Key to the Genera and Species of *Poeciliidae

1a. Dorsal fin rays 5-9, usually 7; caudal fin not modified in males; widespread = *Gambusia holbrooki

1b. Dorsal fin rays 11 or more; lower lobe of caudal fin greatly elongated in a sword-shape in adult males; Gulf and Namak Lake basins = *Xiphophorus hellerii

?pic

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Key to the Genera and Species of Salmonidae

NEEDS to be checked ?

1a. Teeth in lower jaw absent or weak and brush-like; scales large, 13 or less from dorsal fin origin to lateral line, 100 or less in lateral line CHECK; caudal fin clearly forked ---> 2
1b. Teeth in lower jaw strong and conical; lower jaw long, extending back to or past mid-eye; scales small, 19 or more from dorsal fin origin to lateral line, 115 or more in the lateral line CHECK; caudal fin truncate ---> 3

2a. Mouth small? define; snout projects beyond lower jaw; ?, lower jaw not projecting markedly beyond upper jaw CHECK; teeth in roof of mouth few or absent; head length usually 4 times or more in standard length; body not pike-like; Namak Lake basin = *Coregonus lavaretus

2b. Mouth large?; snout not projecting; lower jaw obviously projecting beyond upper jaw; teeth in roof of mouth in broad bands; head length usually less than 4 times in standard length; body pike-like ?fusiform?'^;[Caspian Sea basin = Stenodus leucichthys

3a. Major anal fin rays 12 or more; anterior edge of preoperculum meeting orbital bones; pyloric caeca 140-249 ---> 4
3b. Major anal fin rays 13 or less; gap between anterior edge of preoperculum and orbital bones; pyloric caeca 23-66 ---> 5

4a.  [Caspian Sea basin] = *Oncorhynchus keta

4b.  [widespread]= *Oncorhynchus mykiss

5a. Body with dark spots on light background; vomer with teeth on head and shaft; lower fins without white leading edge ---> 6
5b. Body with light spots on dark background; vomer with teeth on head only; lower fins with white leading edge [Namak Lake basin] = *Salvelinus fontinalis

6a. ? [Caspian Sea, Lake Orumiyeh and Namak Lake basins and translocated]= Salmo caspius

6b. ? [widespread] = *Salmo trutta

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Key to the Species of Siluridae

1a. Teeth short and weak (not snaggly); upper and lower jaws meeting at an antero-dorsal position; finely serrate or smooth pectoral spine posteriorly; colour dark; Caspian Sea, Lake Orumiyeh and Tedzhen River basins = Silurus glanis

1b.  Teeth robust and long (snaggly, catching on flesh); the upper and lower jaws meet at a dorsal and superior position; distinctly and coarsely serrate pectoral fin spine posteriorly; colour light; Tigris River basin = Silurus triostegus

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Key to the Species of Sisoridae

1a. Head and body dorso-laterally with striated or elongate tubercles; thoracic adhesive apparatus is wider than long; caudal peduncle short (5.9-6.0 in standard length) [Tigris River basin] = Glyptothorax kurdistanicus

  
1b.Head and body dorso-laterally without striated or elongate tubercles; thoracic adhesive apparatus longer than wide; caudal peduncle  long (4.7-5.2 in standard length).  [Gulf and Tigris River basins] = Glyptothorax silviae

© Brian W. Coad ( www.briancoad.com)