Genus Barilius
Hamilton-Buchanan, 1822

The members of this genus are found from Pakistan to Thailand with one species in the Tigris-Euphrates and adjacent basins. Their systematics is still poorly understood and there may be about 25 species.

This genus is characterised by a compressed but slender and small body, having small to moderate sized scales, a decurved lateral line, running for example on the lower part of the caudal peduncle, lateral line complete, incomplete or absent, a short dorsal fin and a long anal fin, no fin spines, a moderate and terminal mouth, barbels absent or in 1 or 2 pairs, short gill rakers, pharyngeal teeth in 3 rows, and usually with dark bands or spots on the flank.

These fishes are found mostly in mountain streams although some are lowland species.

Barilius mesopotamicus
Berg, 1932

Common names

None.

[sboura iraqia in Arabic, Mesopotamian minnow].

Systematics

The holotype, 44 mm total length and 35.4 mm standard length, is in the Zoological Institute, St. Petersburg (ZISP 23955) and is decoloured. The collection date is given by Berg (1949) as 16.IV.1914, as 3.IV.1914 in the ZISP catalogue and 5.IV.1914 in the jar. The first two dates are probably correct, one old style and one new style. The type locality is "Stromgebiete des Tigris, in (Siaret) Seid-Hassan, an der persisch-türkischen Grenze, unter 33°20'n. Br., 46°20'ö. L. Seid-Hassan liegt am Flusse Gawi, welcher sich mit dem Kundschian (Gundschian)-tschai vereinigt; der letztere mündet in den Tigris". Seyyed Hasan (33°06'N, 46°11'E) lies on a tributary of the Kanjan Cham River near the Iranian town of Mehran on the Iran-Iraq border. The tributary is presumably the Gawi River.

Howes (1980) stated that this species has apomorph characters shared with species assigned to Leucaspius Heckel and Kner, 1858 but this seems unlikely on general morphological grounds (Coad, 1982b) and Bianco and Banarescu (1982) concur. It resembles other Barilius in having barbels (none in Leucaspius), a lateral line low on the body (short and mid-body), broad suborbital bones, and flank bars (none) while Leucaspius is unique in having in females a fold of skin in the shape of two, large, rounded papillae around the genital opening. Bianco and Banarescu (1982) state that this species may be generically distinct from South Asian Barilius but do not diagnose a new genus. Bănărescu and Coad (1991) and Bănărescu (1992b) state that its position and biogeographical affinities are uncertain. Berg (1949) considers it closer to Indian species of the genus Barilius than to African ones.

Key characters

The only member of its genus in Iran, this species is easily identified by the pigment pattern, low lateral line, broad suborbital bones and the barbels.

Morphology

The lower jaw bears a small symphysial knob. The mouth is slightly subterminal, oblique and elongate with the mouth corner under the anterior half of the eye. A well-developed barbel has its origin just anterior to the level of the nostril above the upper lip and lies in a groove between the upper lip and the beginning of the suborbital bone series. This barbel can be absent or minute in some fish (females from Habbaniyah, Iraq (Coad and Krupp, 1983)). In addition to these maxillary barbels, a second pair of barbels have their origin slightly above the posterior edge of the mouth in 8 out of 259 fish examined. They are usually rudimentary but may reach 10.7% of head length. Barbels are difficult to see in smaller fish without magnification. The suborbital bone series is large.

Dorsal fin unbranched rays 2-3, usually 3, branched rays 7-9; anal fin unbranched rays 2-3, usually 3, branched rays 10-14, branched pectoral fin rays 11-15 and branched pelvic fin rays 6-8. Lateral line scales 42-58. Lateral line incomplete or complete, rarely terminating at the pectoral fin level. Lateral line decurved and parallel to the ventral body profile from the pelvic fin origin to the caudal peduncle, being 2-3 scales above this profile. On the caudal peduncle the lateral line is below the mid-line while scales on the caudal fin posterior to the hypural plate are perforated in the mid-line. Pectoral and pelvic axillary scales present. Scales are regularly arranged over the whole body but are not strongly imbricate, particularly on the belly and back anterior to the dorsal fin. Anterior flank scales are oval with subcentral anterior focus and a moderate number of circuli. Radii are found principally on the posterior and lateral fields. Anterior field radii are usually absent although 1-2 radii may occasionally be found. Scale radii based on 5 anterior flank scales from 5 fish (40.7-50.7 mm standard length) number 5-11 primary radii, 0-13 secondary radii and 5-23 total radii. Total gill rakers 7-14. Gill rakers are short and rounded, reaching to or part way to the raker below when appressed. Total vertebrae 38-41. Pharyngeal teeth usually 4,5-5,4, often 4,5-5,3 (25% of 20 fish examined), or more rarely in three rows 1,3,5-5,3,1 or 1,4,5-5,4,1. Teeth are hooked at the tip, slender and have a concave grinding surface below the tip. The gut is a simple s-shape.

Meristic values for Iranian specimens are:- branched dorsal fin rays 7(2), 8(32) or 9(2); branched anal fin rays 10(2), 11(19), 12(13) 13(1) or 14(1); branched pectoral rays 11(1), 12(8), 13(23), 14(2), or 15(1); pelvic fin rays 6(1), 7(33) or 8(2); scales in lateral series 42(1), 43(3), 44(3), 45(2), 46(6), 47(6), 48(1), 49(3), 50(4), 51(4), 52(2) or 54(1); total gill rakers 7(4), 8(6), 9(6), 10(7), 11(6), 12(1), 13(1) or 14(1); pharyngeal teeth 4,5-5,4(8), 4,5-5,3(3) or 1,3,5-5,3,1(1); and total vertebrae 39(8), 40(20) or 41(5).

Sexual dimorphism

Unknown.

Colour

Overall colour is a brilliant silver with a golden-yellow glimmer, with the back darker and having a thin median stripe. Scales are highly deciduous and leave a silvery smear on the hand. The flanks have 6-11 roundish dark, grey-green spots, not clearly apparent in live fish. In preserved fish the spots are brown. A median dorsal stripe is variably developed. Fins are lightly pigmented, most melanophores being on the rays rather than the membranes. The anal and paired fins are almost entirely hyaline. The caudal fin may show one or two irregular bars running parallel to the posterior margin. The peritoneum is light to silvery but bears scattered melanophores which give a greyish tinge in preserved fish. Some fish from Iraq (Habbaniyah stream) lacked, or had weakly expressed, flank spots.

Size

Reaches 50.7 mm standard length.

Distribution

This species is found in the Tigris-Euphrates basin, including its Iranian part and the adjacent Gulf basin (Berg, 1932; 1949; Bianco and Banarescu, 1982). Abdoli (2000) also records this species from the Jarrahi, the lower Karun, the lower Dez, the Zohreh, the lower half of the Helleh, and the middle and lower Mand rivers.

Zoogeography

This species is found in the Tigris-Euphrates basin of Turkey, Syria, Iraq and Iran. It does not appear to be common in Turkey, at least in the upper reaches of this basin there, nor in upper reaches of Iranian rivers. The distribution in the Dalaki River of Iran is outside the modern Tigris-Euphrates basin. It is presumably a relict of the late Pleistocene when the Tigris-Euphrates flowed down a drained Gulf receiving tributaries now isolated by the post-Pleistocene rise in sea level (Coad and Krupp, 1983).

Habitat

Found in both running and still water, from small streams only 1 m wide and irrigation ditches to major rivers more than 200 m across. Current is slow to fast but generally an obvious flow is apparent. However one specimen was collected in a fish pond near Ahvaz (ZSM 25701). The collection localities in Iran are all at low altitudes and no fish were taken in Zagros Mountain streams and rivers. Collections were made over mud and pebble substrates in shallow streams or at river margins. The species may also occur at the surface in mid-river but no collections confirm this supposition. Capture temperatures were 12-24°C and conductivity 0.45-10.5 mS. Salinity in drying pools of 20 cm depth in Syria where this species was caught in March had Cl^-1 = 390 mg/l and a salinity of 1.5‰ (Coad and Krupp, 1983).

Age and growth

Unknown.

Food

Gut contents include winged insects (Coleoptera, Heteroptera, Thysanoptera and Diptera) and spiders, suggestive of surface feeding (Coad and Krupp, 1983). Abdoli (2000) also reports Hymenoptera, Brachycera and Culicidae.

Reproduction

Most fish were collected in January when eggs were small but developing suggestive of spring spawning.

Parasites and predators

None reported from Iran.

Economic importance

None.

Conservation

This fish is found in suitable habitats of large rivers and in small ditches and does not appear to be in need of conservation. Vulnerable in Turkey (Fricke et al., 2007).

Further work

Molecular or detailed osteological analyses might reveal its relationships to taxa from the Oriental region.

Sources

Type material: See above (ZISP 23955).

Iranian material: CMNFI, 1979-0120, 3, 19.3-50.7 mm standard length, Bushehr, Dalaki River near Konar Takhteh (29º28'N, 51º21'E); CMNFI 1979-0357, 1, 27.6 mm standard length, Khuzestan, Karkheh River drainage (31º34'N, 48º12'E); CMNFI 1979-0363, 11, 21.4-30.2 mm standard length, Khuzestan, Karkheh River (31º52'N, 48º20'E); CMNFI 1979-0365, 7, 20.0-34.4 mm standard length, Khuzestan, Doveyrich River drainage (32º25'N, 47º36'30"E); CMNFI 1979-0367, 1, 34.2 mm standard length, Khuzestan, Meymeh River (32º44'30"N, 47º09'30"E); CMNFI 1979-0368, 29, 21.6-41.9 mm standard length, Khuzestan, Karkheh River (32º24'30"N, 48º09'E); CMNFI 1979-0372, 2, 30.7-33.1 mm standard length, Khuzestan, Dez River near Chogha Zanbil (ca. 32º02'N, ca. 48º30'E); CMNFI 1979-0377, 3, 28.0-39.4 mm standard length, Khuzestan, Karkheh River (ca. 32º57'N, ca. 47º50'E); CMNFI 1979-0378, 7, 31.9-42.4 mm standard length, Khuzestan, stream tributary to Karkheh River (ca.32º48'N, ca. 48º04'E); CMNFI 1979-0380, 10, 25.3-41.0 mm standard length, Khuzestan, stream tributary to Dez River (ca. 32º10'N, ca. 48º35'E); CMNFI 1979-0381, 7, 24.3-31.2 mm standard length, Khuzestan, stream west of Shushtar (ca. 32º10'N, ca. 48º35'E); CMNFI 1979-0382, 4, 25.9-30.8 mm standard length, Khuzestan, Karun River at Shushtar (32º03'N, 48º51'E); CMNFI 1979-0383, 8, 28.6-34.8 mm standard length, Khuzestan, Ab-e Shur drainage (31º59'30"N, 49º06'E); CMNFI 1979-0384, 3, 26.8-40.8 mm standard length, Khuzestan, Ab-e Shur drainage (32º00'N, 49º07'E); CMNFI 1979-0392, 3, 35.0-39.3 mm standard length, Khuzestan, Zard River (ca. 31º32'N, ca. 49º48'E); CMNFI 1979-0396, 35, 25.1-48.8 mm standard length, Khuzestan, Kheyrabad River (30º32'N, 50º23'30"E); ZSM 25701, 1, 36.5 mm standard length, Khuzestan, fishpond near Ahvaz (no other locality data); ISSB uncatalogued, 1, 48.7 mm standard length, Bushehr, Helleh River (ca. 29º20'N, ca. 51º15'E) (Coad and Krupp, 1983).

Comparative material:- BM(NH) 1974.2.22:1256-1267, 11, 33.7-46.2 mm standard length, Iraq, stream between Lake Habanniyah and Euphrates River (ca. 33º22'N, 43º34'E); BM(NH) 1968.12.13:217-220, 4, 18.5-47.4 mm standard length, Syria, Euphrates River at Mayadine (35º01'N, 40º27'E); BM(NH) 1968.12.13:221-236, 16, 30.8-42.4 mm standard length, Syria, Tigris River at Ain Diwar (37º17'N, 42º11'E); SMF 16442, 5, 28.2-35.9 mm standard length, Syria, Nahr Balikh at Jisr Shanine (36º03'N, 39º06'E); SMF 16443, 63, 17.0-34.9 mm standard length, Syria, Nahr Balikh at Jisr Shanine (36º03'N, 39º06'E); ISSB uncatalogued, 4, 32.8-34.4 mm standard length, Turkey, Batman Suyu (ca. 37º55'N, ca. 40º15'E) (Coad and Krupp, 1983).

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