Alosa caspia (Eichwald, 1838)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 64-65

Alosa caspia

Common name. Caspian shad.

Diagnosis. Distinguished from other species of Alosa in Caspian basin by: ● head length 25–28 % SL / ○ eye diameter 19–24 % HL / ○ pectoral length 16–18 % SL / ○ teeth on palatine and vomer poorly developed / ○ 70–180 gill rakers, long, and close together, 1.5–2 times longer than branchial filaments in individuals longer than 150 mm SL. Size up to 280 mm SL.

Distribution. Caspian Sea, from where adults occasionally ascend the lowermost part of rivers and migrate a short distance upstream to spawn.

Habitat. At sea, pelagic, in coastal waters with steady currents, avoiding areas of stable salinity. Migrates from sea to mouths of large rivers, spawns in fresh or slightly brackish water in shallow areas washed by large river currents.

Biology. Anadromous. Males migrate upstream at 2–3 years, females at 4–5 years. Many individuals spawn in 2–4 seasons. Two migration peaks, one in late April (mostly males) and one in early May (mostly females), enter rivers when temperature rises above 10°C. Spawns when temperature reaches 15°C or more, in May–June. Spawns usually in upper 3 m. Eggs semipelagic and demersal. Spent fish return to sea. Juveniles migrate to sea during their first summer and remain at sea until maturity. At sea feeds mainly on zooplankton such as copepods and mysids.

Conservation status. LC; widespread.

Further reading. Heckman 1991a (biology).

Alosa immaculata ; South Bug, Ukraine; 217 mm SL.