Oxynoemacheilus euphraticus

Common name. Fırat loach.

Diagnosis. Distinguished from other species of Oxynoemacheilus in Euphrates and Tigris drainages by: ○ two distinct and prominent black blotches at posteriormost caudal base, often overlaid by a dark-brown or black chevron-shaped bar / ○ lateral line complete / ○ juveniles larger than 20 but smaller than 45 mm SL with poorly developed mottling between midlateral blotches on flank / ○ last bars on caudal peduncle as wide or wider than interspaces / ○ upper lip with well-developed median incision / ○ flank covered by scales / ○ caudal forked / ○ caudal peduncle without high adipose crest or ridge / ○ suborbital groove present in male / ○ caudal peduncle, and in some individuals also flank, with bars / ○ caudal–peduncle depth 2.0–2.8 times in caudal–peduncle length. Size up to 70 mm SL.

Distribution . Euphrates, Tigris, and Karun drainages.

Habitat. Streams and rivers with gravel substrate and fast to very fast-flowing water.

Biology. No data.

Conservation status. LC.

Remarks. The distribution of this species is still incompletely known and it is not recorded from Lesser Zab and Meymeh. It is superficially very similar to O. kurdistanicus and O. marunensis, and these species appear to have formed hybrid populations in some parts of the Tigris drainage. Oxynoemacheilus freyhofi from the Karun drainage is a synonym.

Further reading. Bănărescu & Nalbant 1964 (description); Jouladeh-Roudbar et al. 2016e (description as O. freyhofi); Freyhof & Özuluğ 2017 (synonyms).