Squalius cappadocicus

Common name. Anatolian chub.

Diagnosis. Distinguished from other species of Squalius in Central Anatolia, Marmara, and Black Sea basin, and upper Euphrates by: / ○ anal membranes whitish, yellowish, very pale-orange grey or blackish, rays usually blackish in life, in adults larger than 150 mm SL / ○ 38–44+2 lateral-line scales / ○ dorsal origin above pelvic base / ○ 14–15 circumpedunclar scales / ○ scale pockets on flank with a dark-brown or grey crescent-shaped mark or spot or roundish blotch on middle of flank scale / ○ mouth terminal or subterminal in adults, upper lip projecting beyond lower lip or both lips at equal level / ○ (7½) 8½, very rarely 9 ½ branched anal rays / ○ posteriormost point of anal at tip of 3 rd –5 th branched rays / ○ anal height 14–18 % SL / ○ head length 25–32 % SL / ○ belly between anus and posterior extremity of pelvic base rounded or very slightly compressed / ○ 11–12 gill rakers. Size up to 350 mm SL.

Distribution. Anatolian Black Sea coast west of Çoruh. Eastern tributaries of Sakarya and in Melendiz drainage (Tuz basin). Seyhan, and few tributaries in upper Euphrates including Kangal and Tohma.

Habitat. Streams and rivers stretches with moderate currents, also in reservoirs and lakes.

Biology. Lives up to 7 years. Spawns April–June in shallow gravel bottom areas. Omnivorous, feeding mainly on insects and aquatic invertebrates.

Conservation status. LC.

Remarks. The taxonomy and distribution of S. cappadocicus remain unresolved. It shares the COI sequence data with S. orpheus; both are well distinguished morphologically and supported as two species by unpublished nuclear DNA data. We restrict S. orpheus to Europe and preliminarily identify all Anatolian populations with COI sequences of S. orpheus as S. cappadocicus, the first name available for these fishes. COI and nDNA demonstrate S. adanaensis and S. seyhanensis to be conspecific. Both are identical to S. cappadocicus (and S. orpheus) by their COI sequences. Squalius cappadocicus and S. seyhanensis are very similar morphologically, and the morphological characters proposed to distinguish them could not be confirmed by us. We preliminarily identify S. adanaensis, S. seyhanensis, and all populations from the Black Sea basin having the COI of S. orpheus as S. cappadocicus. More research on nDNA might resolve this complicated situation in the future.

Further reading. Kottelat & Economidis 2006 (description); Özuluğ & Freyhof 2011 (description of S. cappadocicus); Turan et al. 2013b (description of S. adanaensis and S. seyhanensis); Özcan & Serdar 2019 (biology).