Genus Acanthalburnus
Berg, 1916

This genus contains only 2 species, both found in Iran. Berg (1948-1949) characterises it as similar to Alburnoides but with the last unbranched dorsal fin ray thickened into a spine which is strong basally but becomes thinner and flexible on about the last third of the ray length. Pharyngeal teeth are in 2 rows as opposed to 1 row in Abramis. Durand et al. (2002) include this genus in the Abramis clade based on cytochrome b data.

Acanthalburnus microlepis
(De Filippi, 1863)

Common names

مرواريد ماهي لب نازك (= morvaridmahi-e labnazok), kuli.

[garagas or taxta balig, both in Azerbaijan; chernobrovka and napota in Russian; blackbrow bleak].

Systematics

Abramis microlepis was described from the "Kur, presso Tiflis" (= Kura River near Tbilisi, Georgia) and the holotype is in the Istituto e Museo di Zoologia della R. Università di Torino under MZUT N.673 (Tortonese, 1940; Eschmeyer et al., 1996).

Alburnus punctulatus Kessler, 1877, described from the Kura River at Tiflis (= Tbilisi) and Borzhom, Georgia, is a synonym. A syntype of Alburnus punctulatus from the St. Petersburg Museum, 84.6 mm standard length, from "R. Kura, Tiflis" is in the Natural History Museum, London (BM(NH) 1897.7.5:34).

Alburnus Brandtii is apparently a manuscript name for this species first reported without a formal description in Brandt (1880) and listed as "Alburnus Brandtii n. sp. 1 ex. Tschaldyr" and attributed to K. Kessler in the account of the travels of Professor A. F. Brandt in Transcaucasia (see Kavraiskii, 1897). Bogutskaya (1997b) lists it as a nomen nudum.

Alburnus microlepis of Kamensky (1901), which is Acanthalburnus microlepis, should not be confused with Alburnus microlepis Heckel, 1843, a distinct species described from Aleppo (= Haleb, Syria).

Key characters

This species is distinguished from A. urmianus by having more lateral line scales, more anal fin branched rays, fewer gill rakers and gill raker morphology according to Saadati (1977). Gill raker counts are the same but scale and anal fin ray counts are generally higher with some overlap. Gill raker morphology does not appear to differ in the fish examined by me. Distribution is the easiest separating factor. Both species are distinguished from other cyprinids in Iran by the dorsal fin spine, 2 rows of pharyngeal teeth, and fin ray and scale counts.

Morphology

Dorsal fin with 3 unbranched and 7-9, usually 8, branched rays, anal fin with 2-4, usually 3, unbranched and 12-19, usually 15-17, branched rays. Pectoral fin branched rays 12-17 and pelvic fin rays 7-9. Lateral line scales 60-87. There is a large pelvic axillary scale. Scales at the base of the anal fin are somewhat enlarged and may be vertically elongate, forming a sheath. The scale focus is sub-central anterior with fine but not numerous circuli and very few posterior radii (less than 10 main radii in the largest fish seen).

Gill rakers 6-12 and sickle-shaped (Saadati, 1977) but this count presumably includes only lower arch rakers. Total gill rakers 10-14, short and only reaching the adjacent raker when appressed. The rounded raker has a triangular flap on its internal surface with the tip of the rounded raker projecting. The raker tip may be squarish or even forked in larger fish. The inner edge of the flap is finely tuberculate. Vertebrae 40-45. Pharyngeal teeth 2,5-5,2 with variants 2,5-5,1, 1,5-5,2, 1,5-5,1, 3,5-5,2, 2,5-4,2, 2,5-4,1, 2,4-5,1, 2,4-4,1 1,5-4,1, 1,5-4,0, 1,4-5,2, 1,4-5,1 and 2,6-5,2. The teeth are hooked at the tip with an elongate flat area below and the largest tooth may be strongly serrated. The posteriormost major row tooth may be almost vertically above the fourth tooth rather than posterior to it. The last unbranched dorsal fin ray is thickened in its lower two-thirds but the last third is thin and flexible. There is an obvious scaleless keel from the pelvic fins to the vent on the belly mid-line. The mouth is oblique and subterminal in adults and most young, oblique and terminal in some young. The gut is relatively short with anterior and posterior loops.

Both males and females, as well as young, may have fine tubercles distributed over the head and especially well-developed ventrally and even on the lips. Belly and lower flank scales have fine tubercles concentrated at the base of the exposed scale, some lining the scale margin. Fine tubercles line the dorsal and ventral surfaces of the pectoral and pelvic fins concentrated on rays but also on membranes, in a single file or variably dispersed.

Meristic values for Iranian specimens are:- dorsal fin branched rays 7(1) or 8(52); anal fin branched rays 14(4), 15(23), 16(24) or 17(2); pectoral fin branched rays 14(3), 15(36), 16(11) or 17(3); pelvic fin branched rays 8(53); lateral line scales 60(1), 62(2), 63(4), 64(6), 65(11), 66(6), 67(7), 68(4), 69(3), 70(5), 72(1) or 73(2); total gill rakers 10(1), 11(4), 12(18), 13(22) or 14(8); total vertebrae 43(2), 44(10) or 45(13); pharyngeal teeth modally 2,5-5,2(33) with variants 2,5-5,1(6), 1,5-5,2(3) or 1,5-5,1(2).

Sexual dimorphism

Unknown.

Colour

The back and upper head are olive-green to green and the upper flank has a golden sheen. Flanks below are silvery and the abdomen is silvery-white. There is a dark and wide stripe (about orbit diameter) on the flank, not always evident in fresh fish. Above the dark stripe is a narrow golden stripe, about one-third orbit diameter. Dorsal and caudal fins have black tips while paired fins can have a reddish or orange base. The peritoneum is brown with dark blotches or speckles.

Size

Reaches 25 cm.

Distribution

Found in the Kura River of Azerbaijan as far down as Mingechaur but not the lower reaches. In Iran it is found in the Caspian Sea basin including the Aras River shared with Azerbaijan and Iran, as far down as Karadonly, and in the Qarasu a tributary of the Aras. Reported from the Safid River basin (Abbasi et al., 1999; Kiabi et al., 1999; Abdoli, 2000; Jolodar and Abdoli, 2004) and in the Anzali Talab drainage. Records from the middle Agi Chai or Talkheh River near Tabriz and the Zarrineh River of the Lake Orumiyeh basin are presumably of A. urmianus (Abdoli, 2000).

Zoogeography

The genus and its two species are restricted to the Caspian Sea basin and the adjacent Lake Orumiyeh basin and are presumably derived from a common ancestor related to the Alburnoides-Alburnus lineage.

Habitat

This species inhabits both rivers and lakes.

Age and growth

Females mature at 2 years (Abdurakhmanov, 1962). Spawning probably occurs in the spring judging from fish caught on 31 January which had developing eggs. Türkmen et al. (2001) found fish to 7 years of age in the upper Aras River in Turkey, with three-year-old fish dominant, and also gave length-weight and length-age relationships. Females attained a greater age and size than males.

Food

Food includes aquatic insects, crustaceans and snails, and detritus.

Reproduction

Fecundity is up to 19,060 eggs and egg diameter to 1.87 mm. In Armenia maturity is reached at the end of the second year or beginning of the third year at 80-120 mm and spawning takes place in late April to early May and may continue to late August (Pipoyan and Arakelyan, 1999). In the Turkish Aras, maturity for both sexes began at age 2 years, with all fish mature at 4 years, and spawning started in early May and continued to the end of July. Fecundity reached a mean value of 9705 eggs and egg size reached 1.65 mm (Türkmen et al., 2001).

Parasites and predators

None reported from Iran.

Economic importance

None.

Conservation

Kiabi et al. (1999) consider this species to be conservation dependent in the south Caspian Sea basin according to IUCN criteria. Criteria include sport fishing, few in numbers, habitat destruction, 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 of this species has not been investigated and its population biology is also unknown.

Sources

Type material: See above, syntype of Alburnus punctulatus (BM(NH) 1897.7.5:34).

Iranian material: CMNFI 1970-0522, 2, 55.1-71.3 mm standard length, Gilan, Safid River at Astaneh Bridge (37º16'30"N, 49º56'E); CMNFI 1970-0536, 4, 70.9-109.3 mm standard length, Gilan, Siah River estuary (36º53'N, 49º32'E); CMNFI 1970-0538, 1, 70.7 mm standard length, Gilan, Qezel Owzan River (ca. 36º44'N, ca. 49º24'E); CMNFI 1970-0583, 11, 39.0-79.9 mm standard length, Gilan, Nahang Roga River (37º28'N, 49º28'E); CMNFI 1979-0454, 8, 37.7-64.7 mm standard length, Zanjan, Qezel Owzan River at Gilavan (36º47'N, 49º08'E); CMNFI 1979-0455, 7, 50.2-123.3 mm standard length, Markazi, Manjil Dam (36º45'N, 49º17'E); CMNFI 1979-0695, 15, 71.6-112.7 mm standard length, Gilan, Safid River at Manjil Bridge (36º46'N, 49º24'E); CMNFI 1980-0116, 1, 75.5 mm standard length, Gilan, Safid River at Astaneh Bridge (37º16'30"N, 49º56'E); CMNFI 2007-0087, 4, mm standard length, Azarbayjan-e Khavari, Qareh Su (38º22'N, 48º19'E).

Comparative material: CMNFI 1980-0807, 2, 138.2-143.8 mm standard length, Turkey, Ölçek Suyu (no other locality data); CMNFI 1986-0007, 1, 132.2 mm standard length, Turkey, Kars River (ca. 41º00'N, ca. 43º00'E).

Acanthalburnus urmianus
(Günther, 1899)

 Common names

None.

Systematics

Originally described in the genus Abramis Cuvier, 1816, Berg (1948-1949) placed this species in the genus Alburnoides Jeitteles, 1861 but Saadati (1977) places the species in this genus.

The type material in the Natural History Museum, London comprises 2 specimens, 54.9-58.6 mm standard length, from the Urmi River (BM(NH) 1899.9.30:116-117), 1 specimen, 111.7 mm standard length, from the Ocksa River (BM(NH) 1899.9.30:118) (these three fish being labelled paralectotypes, with 118 being the lectotype, by P. M. Bănărescu in 1980), and 8 specimens, 50.5-111.7 mm standard length, from the Ocksa River (BM(NH) 1899.9.30:119-126), these being syntypes. Günther (1899) refers to the type series as "Five specimens from the Gader Chai and two small ones from the Urmi River; the largest is only 144 millim. long" so there is some confusion over this material.

Key characters

This species is distinguished from A. microlepis by having fewer lateral line scales, fewer anal fin branched rays, more gill rakers and gill raker morphology according to Saadati (1977). Gill raker morphology does not appear to differ in the fish examined by me. Gill raker counts are the same but scale and anal fin ray counts are generally lower with some overlap. Distribution is the easiest separating factor.

Morphology

Dorsal fin with 3 unbranched and 7-9, usually 8, branched rays, anal fin with 3 unbranched and 10-13 branched rays. Pectoral fin branched rays 14-16 and pelvic fin branched rays7-8. Lateral line scales 50-68. Scales bear only a few posterior radii and have a subcentral anterior focus. A pelvic axillary scale is present. Gill rakers 10-14, short not quite or just reaching the adjacent raker when appressed; rounded with a projected tip and distinct from its congener according to Saadati (1977) but closely resembling the structure seen in A. microlepis according to my observations (see above under A. microlepis). Pharyngeal teeth usually 2,5-5,2 or 2,5-4,2 with variants 2,4-5,2, 1,5-4,2 or 2,4-4,2. Posterior teeth are hooked at the tip, anterior teeth being rounded, and have no, slight, moderate or even strong serrations. There is a narrow and slightly concave surface below the tip. Some fish have the anterior margin of the concave surface higher than the posterior margin, but this is variable and in some teeth the condition is the reverse. The ventral keel extends from the anus to the base of the pelvic fins and is fleshy from half way to the whole length. The intestine is an elongate s-shaped with a small anterior loop. Total vertebrae 41-43.

Meristic values for Iranian specimens are:- dorsal fin branched rays 7(1), 8(20) or 9(1); anal fin branched rays 10(1), 11(4), 12(11), or 13(6); pectoral fin branched rays 14(4), 15(17) or 16(1); pelvic fin branched rays 7(3) or 8(19); lateral line scales 50(1), 52(2), 53(2), 55(1), 56(1), 57(2), 59(2), 60(3), 61(3), 62(2), 63(1), 64(1) or 68(1); total gill rakers 10(1), 11(2), 12(6), 13(8), or 14(5); pharyngeal teeth 2,5-5,2(1), 2,5-4,2(1), 2,4-5,2(1) or 2,4-4,2(1); total vertebrae 41(5), 42(7) or 43(2).

Sexual dimorphism

Male fish bear tubercles but fully tuberculate fish have not been examined. One male, 94.7 mm standard length, had a single row of tubercles on anterior pectoral fin rays.

Colour

Overall colour is silvery with a greenish-olive back and flanks with numerous minute brown pigment spots which are crowded above the lateral line to form an inconspicuous darker stripe along the whole side. The dorsal, caudal and pectoral fins have a light to evident speckling of melanophores on the rays and membranes but are almost immaculate in preserved specimens. Larger fish have pigment proximally on the anterior anal fin rays. The peritoneum is silvery but densely speckled with melanophores.

Size

Reaches 15.6 cm standard length, almost 20 cm in total length.

Distribution

This species is endemic to the Lake Orumiyeh basin, apparently in southern and western tributaries (Günther, 1899) although records of A. microlepis from the middle Agi Chai or Talkheh River near Tabriz are presumably of A. urmianus (Abdoli, 2000).

Zoogeography

The closest relative and only congener, Acanthalburnus microlepis, is found in the Caspian Sea basin. Connections between the Lake Orumiyeh basin and the Caspian Sea basin have been suggested by Saadati (1977), an early one in the Pliocene to early Pleistocene resulting in endemic species and a later one in the late Pleistocene resulting in species which are the same as the Caspian or only subspecifically distinct. This species presumably dates from the earlier connection (but see the Lake Orumiyeh drainage basin account for more details).

Habitat

Details of habitat requirements are unknown but is has been collected in both river and lakes.

Age and growth

Fish are mature at 14.4 cm. This species is relatively fast-growing, short-lived species with males attaining 6+ years and females 7+ years in the Kazemi Dam on the Zarrineh River (Abdoli et al., 2008). The von Bertalanffy growth curve was estimated as K = 0.427 in males and 0.506 in females, indicating that females grow faster. The sex ratio was 598♂:912♀ and there were no significant differences between males and females in the linear length-weight relationships.

Food

Diet is generally unknown and guts examined were empty except for a few plant and crustacean remains.

Reproduction

Reproductive data is unknown although this species probably spawns in the spring as do most members of this family.

Parasites and predators

None reported from Iran.

Economic importance

None.

Conservation

This species is known only from the type series and a few other specimens in museum collections. Its status is unknown.

Further work

Field work should be carried out to determine the habitat requirements, ecology and numbers of this uniquely Iranian fish.

Sources

Type material: See above (BM(NH) 1899.9.30:116-117,  BM(NH) 1899.9.30:118, BM(NH) 1899.9.30:119-126).

Iranian material: CMNFI 1979-0093, 2, 127.5-130.5 mm standard length, Azarbayjan-e Bakhtari, Lake Qowpi (36º57'N, 45º52'E); CMNFI 2007-0098, 1, 156.3 mm standard length, Azarbayjan-e Bakhtari, river south of Mahabad (ca. 36º42'N, ca. 45º41'E); CMNFI 2007-0101, 1, 129.3 mm standard length, Azarbayjan-e Bakhtari, Tata'u River south of Miandow Ab (ca. 36º54'N, ca. 46º07'E); CMNFI 2007-0105, 1, 90.8 mm standard length, Kordestan, Zarineh River basin south of Saqqez (ca. 36º06'N, ca. 46º20'E); USNM 205904, 1, 84.7 mm standard length, Azarbayjan-e Bakhtari, Nazlu-chay near Rezaiyeh (37º40'N, 45º05'E); USNM 205934, 2, 94.5-141.9 mm standard length, Azarbayjan-e Bakhtari, Lake Qowpi (36º57'N, 45º52'E);  uncatalogued, 4, 105.1-134.9 mm standard length, Azarbayjan-e Bakhtari, Zarineh River (no other locality data);