Romanogobio
Bănărescu, 1961

There are about 17 species in the genus found from Europe to China with one species recorded from Iran. Members of the genus have a shallower body than the related Gobio, an elongated, usually cylindrical, caudal peduncle, epithelial keels on dorsal scales, an anus placed closer to ventral fins, absolute or average prevalence of caudal vertebrae over abdominal ones, and a higher number of preanal vertebrae (Naseka, 1996). Bănărescu in Bănărescu and Paepke (2002) notes that he considers Romanogobio as a subgenus and further work is needed to resolve this difference of opinion. Most literature is under the genus Gobio.

Romanogobio persus
(Günther, 1899)

Common names

 گاو ماهي (= gav mahi, probably in error for Neogobius gobies).

[Kur gumlagcisi in Azerbaijan; Kurinskii peskar' or Kura gudgeon in Russian; Persian gudgeon].

Systematics

This species may correctly belong to the genus Rheogobio Bănărescu, 1961 variously regarded as a synonym of Gobio, a subgenus or a distinct genus. P. M. Bănărescu (in litt., 1984) and A. Naseka (pers. comm., 1994; in litt., 1995) place Gobio persus in the subgenus Romanogobius sensu Bănărescu (1961; 1992a) and Naseka (1996) elevates Romanogobio to a genus.

Gobio macropterus Kamenskii, 1901 described from the Kura and Aras River basins was regarded as a synonym, and is now used as a subspecies. Gobio persa is an incorrect spelling.

A. Naseka (pers. comm., 1994; in litt., 1995; Naseka et al. in Bănărescu, 1999) has studied R. persus from the Orumiyeh basin and from the Kars, Kura and Aras rivers of Turkey, Georgia and Azerbaijan. He distinguishes two subspecies, R. p. persus from the Orumiyeh basin and R. p. macropterus Kamenskii, 1901 from the Kura River basin which includes the Kars River in Turkey and the Aras River on the border of Iran and Azerbaijan.

The type series of Gobio persa consists of 7 specimens, 53.1-65.9 mm standard length, in the Natural History Museum, London from "Ocksa in the Gader Chai" in the description and "Ockra. NW Persia. Günther" in the jar, the former being more accurate (BM(NH) 1899:30:90-96). The 14 specimens in the type series of Gobio macropterus were deposited in the Georgian State Museum, Zoological Section, Tbilisi (ZMT) and in Kharkov University, Ukraine. Naseka et al. in Bănărescu (1999) cites types of Gobio macropterus in the Museum of the Caucasus (Tbilisi, presumably the Georgian State Museum) under numbers 128a (1 fish from Alazan) and 129 (4 fish from Kars-tschai) and 1-2 fish from the Kura (catalogue number unknown) in Khar'kov University.

Key characters

The 7 branched dorsal fin rays are characteristic and this is the only Romanogobio species in Iran. It is separated from the only other related species in Iran (Gobio gobio) by having the body only slightly compressed and the caudal peduncle being cylindrical (caudal peduncle depth at anal fin insertion less than or about equal to caudal peduncle width) and by faint spots on the dorsal and caudal fins.

A. Naseka distinguishes the subspecies by the following key:-

1(2) 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 R. p. persus.

2(1) 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 R. p. macropterus.

The Orumiyeh fish also have a shorter caudal peduncle, a shorter snout, a shorter barbel, and a longer predorsal distance.

Morphology

The barbel is broad and fleshy, the mouth subterminal and horseshoe-shaped with thick, papillose lips. The lower head surface between the jaws and the sides of the head are papillose in a mature female.

Dorsal fin with 3, rarely 4, unbranched and 7, rarely 8, branched rays, anal fin with 3, rarely 2, unbranched and 5-7, usually 6, branched rays, pectoral fin branched rays 11-16, and pelvic fin branched rays 6-8. Lateral line scales 39-45. A pelvic axillary scale is present. The throat, breast and anterior belly are naked. Dorsal scales bear epithelial keels, usually one central keel and one to several lateral ones. Scales have a very anterior focus and few posterior radii. Gill rakers 0-6, small and irregularly spaced. Vertebrae 36-42. Pharyngeal teeth 2,5-5,2 or 3,5-5,3, or more rarely 2,5-5,1, 2,5-5,3, 2,4-5,3, 2,4-6,3, and 3,5-5,2. Teeth are strongly hooked at the tip, broadly concave or flattened below the tip, the surface sloping medially. The gut is s-shaped with a slight anterior loop to the left. The anus lies between the pelvic fins, remote from the anal fin origin. The karyotype is 2n=50.

Meristic counts in Iranian fish are: dorsal fin branched rays 7(22); anal fin branched rays 6(21) or 7(1); pectoral fin branched rays 11(1), 12(1), 13(6), 14(7), 15(6) or 16(1); pelvic fin branched rays 7(22); lateral line scales 39(3), 40(7), 41(3), 42(2) or 43(2); pharyngeal teeth 3,5-5,3(5); and total vertebrae 37(1), 38(7), 39(10), 40(4), 42(1).

Sexual dimorphism

Males and females bear irregular-shaped, elongate tubercles on the head. In a female specimen (and presumably males too), the pectoral and pelvic fin rays and adjacent membranes bear tubercles both dorsally and ventrally although the latter are less well developed. Males have longer pectoral and pelvic fins than females, reaching the pelvic fin and anal fin origin respectively in males. The snout to anus distance is more than half body length in females and about equal in males, head width is less than head depth at nape in females and equal in males, and snout length is longer than postorbital distance in females and about equal in males.

Colour

The upper flank is a light yellow-grey to brown with each scale outlined with, or partially filled in with, dark pigment, fading to a yellowish colour below. The mid-flank has 6-12 elongate to rectangular black spots. The lateral line pores may have small dark spots above and below reminiscent of Alburnoides bipunctatus. The back also bears vague dark spots. Dorsal, caudal and pectoral fins bear up to 5 thin to broad discontinuous bars, the pigment being on the rays. Scales above the lateral line in mature males have longitudinal streaks. Peritoneum silvery with scattered melanophores.

Size

Reaches 10.5 cm standard length, perhaps 15 cm (Geldiay and Balık, 1996).

Distribution

Found in the Kura and Aras river basins of Armenia, Azerbaijan and Iran and in the Lake Orumiyeh basin (Günther, 1899). Abdoli (2000) maps the middle Aras River and its lower Qara Chai tributary; the middle and lower Talkheh, lower Tatavi and Zarrineh rivers in the Lake Orumiyeh basin.

Zoogeography

This species is part of a gobionine fauna found across Eurasia and this wide distribution may be suggestive of further work that could be done to clarify relationships of these fishes.

Habitat

This species favours running water, probably shallow and fast, and presumably sand and gravel bottoms.

Age and growth

Life span is 3 years with sexual maturity attained at 2-3 years.

Food

The principal food is aquatic insects, such as chironomids, caddis flies and mayflies, and crustaceans but detritus and vegetation are also taken and rarely the eggs and fry of such fishes as sturgeons. The chitinous remains of aquatic insects comprised 30% of the gut contents from samples in the Kura River basin, caddisflies 21%, mayflies 14%, chironomids 12%, sevryuga eggs 6%, fish scales 3%, and much of the remainder was detritus at 20% (Abdurakhmanov, 1962). Abdoli (2000) lists Trichoptera, Ephemeroptera and Chironomidae as food items.

Reproduction

Spawning takes place in May in Azerbaijan (Abdurakhmanov, 1962) and each female may spawn several times in a season. An Iranian specimen had relatively large eggs (1.2 mm) when captured on 23 June. Eggs number up to 15,840 and are up to 1.62 mm in diameter. Water temperatures of 12-18°C are recorded for Georgia in April to June (Naseka et al. in Bănărescu, 1999).

Parasites and predators

None reported from Iran.

Economic importance

None, although its recorded habit of feeding on sturgeon eggs may make it important in Caspian Sea drainages.

Conservation

The type subspecies is apparently endemic to the Lake Orumiyeh basin where few specimens have been caught and deposited in museums. The numbers of this species in the wild are unknown. Vulnerable in Turkey (Fricke et al., 2007).

Further work

The biology of this species, and its conservation status, have not been thoroughly investigated.

Sources

Type material: See above, BM(NH) 1899:30:90-96.

Iranian material: CMNFI 1980-0155, 3, 45.9-69.3 mm standard length, Azarbayjan-e Khavari, Qareh Su near Ardebil (ca. 38º15'N, ca. 48º18'E); CMNFI 2007-0101, 12, 28.8-64.3 mm standard length, Azarbayjan-e Bakhtari, Tat'u River (ca. 36º54'N, ca. 46º07'E).

Comparative material: CMNFI 1980-0806, 1, 93.4 mm standard length, Turkey, Kars Çayi, Kars (40º37'N, 43º05'E); CMNFI 1986-0007, 4, 49.4-84.0 mm standard length, Turkey, Kars, Kars Çayi north of Kars (41º00'N, 43º00'E).

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© Brian W. Coad (www.briancoad.com)