Cobitis splendens

Common name. Bithynian spined loach.

Diagnosis. Distinguished from other species of Cobitis in Black Sea basin and endorheic Anatolian basins of Lakes Akşehir, Eber and Ilgın by: ○ pigmentation in Z3 reduced to about head length in male or pigmentation in Z3 as wide as or narrower than pigmentation in Z2 / ○ blotches in Z4 irregularly roundish or squarish anterior to dorsal origin / ○ focal zone of subdorsal scale small, about 1⁄3–1 ⁄10of verti - cal scale diameter / ○ one lamina circularis in male / ○ base of lamina circularis with a narrow connection to pectoral ray. Size up to 86 mm SL.

Distribution . Türkiye: Small coastal streams around Akçakoca and Büyük Melen (Black Sea).

Habitat. Lower and middle reaches of still to moderately fast-flowing, clear streams with mud or sand bottoms.

Biology. No data.

Conservation status. LC; Population may be stable, but more data is needed.

Remarks. Doubtful records of this species from Aegean and southern Marmara basins could not be confirmed and seem to be based on misidentifications of C. satunini and C. fahireae . A reduced pigmentation in Z 3 in male is very characteristic to C. splendens . Still, this character state is not unique to C. splendens, and individual males with very much reduced or even no pigmentation in Z3 are found in many other Cobitis species. Cobitis from the Büyük Melen [entering Black Sea at 41.073, 30.967] are identified as C. splendens based on molecular characters. Still, in this population, the pigmentation in Z3 is not reduced, distinguishing it from C. splendens . The Cobitis of Anatolian Black Sea basin needs an in-depth revision.

Further reading. Erk’akan et al. 1998 (description); Erk’akan et al. 1999 (distribution); Freyhof et al. 2018c (description, distribution, Büyük Melen).