Oxynoemacheilus bergianus

Oxynoemacheilus bergianus View in CoL View Figure

Common name. Sportive loach.

Diagnosis. Distinguished from other species of Oxynoemacheilus in Seyhan, Black Sea, and Caspian basins as wellasEuphratesandTigrisdrainagesby:○ caudal–peduncle depth 6–10 % SL, usually 2.0–3.0 times in its length, very rarely 1.8–3.5, without high adipose crest or ridge / ○ caudal deeply emarginate, middle caudal ray 70–84 % of length of longest ray in upper caudal lobe / ○ lateral line complete / ○ flank covered by scales / ○ upper lip without a median incision / ○ suborbital groove present in male / ○ one central or no black, grey, or brown blotch or short bar on caudal base, its colour identical to blotches on caudal peduncle / ○ no yellowish triangles at posteriormost portion of caudal peduncle / ○ pelvic very long, reaching or almost reaching to anus / ○ pectoral in male very long, reaching or almost reaching to pelvic origin / ○ flank mottled, marmorate, or with large, irregularly shaped, squarish, or vertically elongate blotches, usually as wide or narrower than interspaces / ○ lateral blotches on caudal peduncle usually interrupted in size and/or shape at or above lateral midline. Size up to 71 mm SL.

Distribution View Figure . Kızılırmak drainage in Anatolian Black Sea basin, upper Zamantı (Seyhan) drainage in Mediterranean basin, upper Euphrates and upper Tigris including Greater Zab, Sirvan south to Doiraj, and Meymeh. Also, in Caspian basin, from Sefid in Iran north-west to Aras and Lake Namak and Urmia basins.

Habitat. Moderate to fast-flowing waters with coarse gravel and small boulders.

Biology. No data.

Conservation status. LC.

Remarks. This is the most widespread of all Oxynoemacheilus species. Oxynoemacheilus erdali from the upper Murat drainage in Türkiye, O. lenkoranensis from Azerbaijan, O. longipinnis and O. parvinae from Iran, and O. samanticus from Seyhan in Türkiye are synonyms. No consistent morphological or colour pattern differences between these populations have been found or confirmed, and they show very small molecular differences. Recently published morphological differences are fabricated to support populations with very small molecular differences as separate species. Oxynoemacheilus longipinnis has been described as a separate genus, Ilamnemacheilus , based on a malformed individual with 10½ branched dorsal rays, several multiplied vertebrae, and a shortened caudal peduncle.

There appear to be no records of O. bergianus from the Kura drainage, but further fieldwork is required to confirm its presence. If this species is found to be conspecific with O. bergi from the Kura, then O. bergi would take precedence over O. bergianus . No external characters are known to distinguish O. bergianus from O. banarescui , O. fatsaensis , and O. simavicus , all of which are diagnosed by molecular characters. Published morphological differences are based on small sample sizes or are intentionally falsified.As these four species are allopatric, the range should aid identification.

Further reading. Derjavin 1934 (description); Abdurakhmanov 1962 (description of Nemacheilus lenkoranensis ); Balık & Bănărescu 1978 (description of O. samanticus ); Coad & Nalbant 2005 (description of Ilamnemacheilus longipinnis ); Erk’akan et al. 2007 (description of O. erdali ); Freyhof 2016a (generic position of I. longipinnis ); Sayyadzadeh et al. 2016 (description of O. parvinae ); Sayyadzadeh et al. 2017 (re-description of O. longipinnis ); Kaya et al. 2016 (distribution); Freyhof 2022 (revision of O. bergianus group).