Alburnus demiri, Ozulug & Freyhof, 2008

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 314-315

Alburnus demiri

Common name. Eastern Aegean bleak.

Diagnosis. Distinguished from other species of Alburnus in Central Anatolia, Aegean, Marmara, and Black Sea basins by: ○ 43–46+3 scales in lateral line / ○ 13–14½ branched anal rays / ○ 9 scale rows between lateral line and dorsal origin / ○ 18–21 gill rakers / ○ ventral keel exposed for 6–9 scales in front of anus / ○ caudal peduncle depth 10.5–11.1 % SL. Size up to 90 mm SL.

than males. Anadromous populations enter rivers in autumn (September in Kura) and migrate upstream in winter and/or spring. Spawns May–September in water 0.2–0.7 m deep, current about 1 m /s and 18–26°C, often with much splashing. Males appear to be territorial. They congregate at spawning sites and wait for mature females, which arrive later. Eggs stick to pebbles or stones. Embryonic development lasts 2–3 days; larvae initially remain between pebbles for 8–11 days, then actively migrate to shallower areas and backwaters. Many populations are riverine. In migratory populations, adults return to sea, lakes or estuaries soon after spawning to feed. Young juveniles migrate downstream in autumn of same year or following spring. Larvae and juveniles feed on zooplankton, algae, and insect larvae, adults mainly on planktonic crustaceans, terrestrial insects, and small fish. Often hybridises with sympatric Squalius species.

Conservation status. LC.

Further reading. Kazancheyev 1981 (Caspian); Movchan & Smirnov 1983 (morphology, biology); Kottelat & Freyhof 2007 (distribution, biology, diversity Europe); Coad 2021a (biology, morphology).

Distribution. Türkiye:Tahtalı and Küçük Menderes drainages.

Habitat. A wide range of moderately fast-flowing streams and rivers with gravel substrate. Reservoir populations migrate to tributaries to spawn.

Biology. Spawns May–June.

Conservation status. EN; appears to be declining within its very small range.

Further reading. Özuluğ & Freyhof 2008a (description); Mangit & Yerli 2018 (distribution).

Alburnus derjugini ; Dagomys drainage, Russia; 95 mm SL.

Alburnus derjugini ; Bakırçay drainage, Türkiye; 88 mm SL.