Alburnus escherichii

Common name. Sakarya bleak.

Diagnosis. Distinguished from other species of Alburnus in Central Anatolia, Mediterranean, Marmara, and Black Sea basins by: ○ 42–49+3 lateral line scales / ○ 12–16 gill rakers / ○ 12–15½ branched anal rays / ○ pelvic axillary scales present / ○ scales on back, flank, and belly well developed, overlapping/ ○ in life, flank without stripes or golden upper and black lower stripe faint / ○ no mottling on flank / ○ last unbranched dorsal ray soft and flexible / ○ anal origin below dorsal base / ○ ventral keel exposed for 0–5 scales in front of anus / ○ body depth at dorsal origin 24–30 % SL / ○ 8–10 scale rows between lateral line and dorsal origin. Size up to 131 mm SL.

Distribution. Türkiye: Sakarya drainage, Lakes Eber, Akşehir, and Ilgın basins. Locally in Kızılırmak drainage (likely introduced). Introduced in Lake Beyşehir basin and Manavgat drainage and likely elsewhere.

Habitat. A wide range of moderately fast-flowing streams and rivers with gravel substrate. Spawns in fast-flowing waters on gravel beds. Lacustrine populations migrate to inflowing rivers or streams to spawn.

Biology. No data.

Conservation status. LC.

Remarks. Alburnus nasreddini is a synonym.

Further reading. Bogutskaya 1997b (identification); Perea et al. 2010 (phylogeny); Bayçelebi et al. 2020b (distribution, morphology, synonym); Bektaş et al. 2020 (phylogeny).