Sterletus gueldenstaedtii

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 50-51

Sterletus gueldenstaedtii

Common name. Russian sturgeon

Diagnosis. Distinguished from other species of Acipenser and Sterletus in West Asia by: ○ head triangular, if seen from below / ○ base of barbels closer to tip of snout than to mouth / ○ barbels not fimbriate / ○ lower lip interrupted in middle / ○ 15–31 gill rakers / ○ 8–19 dorsal scutes / ○ 24–50 lateral scutes / ○ 6–13 ventral scutes / ○ snout short (22–36 % HL) and blunt / ○ head length 17–19 % TL / ○ many star-shaped bony denticles of various sizes between dorsal

Biology. Non-anadromous. Males first spawn at 11–24 years, females at 20–28 years (9–10 and 11–12 years, respectively, in Lena). Females spawn every 3–5 years and males every 2–3 years in May–June at 9–18°C.In Siberian part of range,there are both sedentary and migratory parts of populations. Migratory individuals feed in estuaries and migrate upstream to spawn. Before construction of dams on Ob, they migrated about 3000 km upstream. Spawning migration begins in autumn. Sedentary individuals inhabit middle and upper reaches of rivers and do not undertake long migrations.Feeds on a variety of benthic organisms,including crustaceans and chironomid larvae.

Conservation status. Non-native and not established; released for commercial fisheries or escaped from fish farms. CR in native range.

Further reading. Sokolov & Vasil’ev 1989b (biology).

and lateral scutes / ○ dorsum golden brown, belly yellowish white / ○ dorsal profiles of head and body forming an obtuse angle / ○ no plates along posterior part of anal base / ○ 0–1 plate along lower edge of caudal peduncle / ○ tetraploid. Size up to 2360 mm TL and 115 kg. Evidence does not support records of size up to 4000 mm TL. Subfossil specimens about 3000 mm TL.

Distribution. Caspian, Black, and Azov Sea basins.

Habitat. At sea, shallow coastal and estuarine areas. In freshwaters, deep parts of large rivers with moderate to fast currents. Spawns in strong currents (1.0– 1.5 m /s) in large and deep rivers on stony or gravelly bottoms.

Biology. Anadromous and freshwater populations.A complex pattern of spawning migrations includes spring and autumn runs. Individuals migrating in spring enter freshwater just before spawning, tend to spawn in lower reaches of rivers ( 320–650 km in unregulated Ural). Individuals migrating in autumn overwinter in rivers and spawn further upstream in spring ( 900–1200 km in Ural).Males first spawn at 8–13 years, females at 10–16 years. Females spawn every 4–6 years and males every 2–3 years in April–June when temperatures rise

Sterletus huso ; Volga, Russia; ~ 1000 mm TL. © A. Hartl.