Barbus rionicus

Common name. Colchic barbel.

Diagnosis. Distinguished from other species of Barbus in West Asia by: ○ flank plain brown or grey with many minute, dark-brown spots, smaller than scales, in individuals over 100 mm SL / ○ lower lip with a median lobe / ○ 50−62, usually 54−58, total lateral-line scales / ○ last dorsal unbranched ray weakly to moderately ossified / ○ 8–12 gill rakers / ○ head length 24−28 % SL / ○ 44−47, usually 45−46, total vertebrae / ○ anal longer in female than in male. Size up to 500 mm SL, but expected to grow larger.

Distribution . Georgia and Türkiye: Eastern Black Sea basin from Kodori south to Rioni and Çoruh.

Habitat. Mountain to hill streams with gravel bottoms and moderate- to fast-flowing water. Prefers stretches with large rocks and rapids alternating with deep holes. Spawns in riffles and rapids.

Biology. Males mature at 2−3 years, 1−3 years earlier than females. Spawns May–September with a peak from May– July at water temperatures of 14−21°C. Spawns in large groups, fractional spawners. Migrates upstream to spawn. Feeds on benthic invertebrates and aquatic plants.

Conservation status. LC.

Further reading. Elanidze 1983 (morphology, biology; as B. tauricus escherichii); Yıldırım et al. 2001 (biology, Çoruh); Bogutskaya et al. 2003c (morphology, biology, as B. tauricus escherichii, partly); Kotlík et al. 2004 (molecular).