Squalius lepidus, Heckel, 1843

Squalius lepidus View in CoL View Figure

Common name. Mesopotamian pike chub.

Diagnosis. Distinguished from S. berak and S. verepi in Persian Gulf basin by: ● lower lip projecting beyond upper lip or tip of both lips equal / ● posterior anal margin straight / ● 9–10½, rarely 8½ branched anal rays / ● 45–60+1–3 lateral-line scales / ● head pointed / ● snout long / ● dorsal head profile straight or concave / ● scale pockets on flank not or moderately covered by pigments forming a grey crescent-shaped blotch, resulting in a poorly contrasted reticulate pattern or reticulate pattern absent. Size up to 350 mm SL, likely to grow larger.

Distribution View Figure . Euphrates, Tigris, and Karun drainages.

Habitat View Figure . Large- to medium-sized rivers, lakes, and reservoirs from where they migrate to tributaries to spawn. Rarely in small streams.

Biology. Spawns May–June.

Conservation status. LC.

Remarks. In medium-sized rivers, it often occurs in sympatry with S. berak (Euphrates) or S. verepi (Tigris) , which inhabits mostly small- to medium-sized streams. Sympatric species occasionally hybridise, as mitochondrial DNA from S. berak and S. verepi is often found in S. lepidus , and there are many populations similar to hybrids between these species (relatively long head). Many individuals “difficult to identify” by the characters may be such hybrids. Chubs identified as S. lepidus from Lake Beyşehir, Lake Akşehir, Ceyhan, and the Orontes belong to other species.

Further reading. Bogutskaya 1994 (description); Coad 2021a (biology, morphology).