It is found in Azerbaijan, Bulgaria, Georgia, Iran, Kazakhstan, Romania, Russia, Turkey, Turkmenistan, and Ukraine. It is also found in the Caspian Sea. This fish can grow up to about 235 cm (93 in) and weigh 115 kg (254 lb). Russian sturgeon mature and reproduce slowly, making them highly vulnerable to fishing. It is distinguished by its short snout with a rounded tip as well as its lower lip which is interrupted at its center.
More than 200,000 individuals were feeding in the north-western part of the Black Sea in the period 1966-1974. The current stock size is unknown but regarded as very low.
Individuals migrating in spring enter freshwater just before spawning and spawn in lower reaches of the river (320-650 km upstream). Individuals migrating in autumn spawn the following spring further upstream (900-1200 km).
The annual catch in ex-Yugoslavia dropped from 14,636 kg in 1983 to 1,636 kg in 1985 (a decline of almost 90%) due to the construction of Iron Gate II dam in 1984, which cut off spawning grounds.
Russian Sturgeon
The Russian sturgeon feeds on crustaceans, molluscs and small fishes such as gobies, anchovies and sprats. It is solitary when in the sea but becomes gregarious as it moves up-river in April, May and June to spawn.
Life expectancy 50 years. Bentophage feeds mainly on mollusks, less often on fish. Populations are represented by winter and spring forms. It spawns from mid-May to early June at a water temperature of 8-15 °C in areas with gravel or rocky soil at depths of 4 to 25 m. Fertility can range from 50 to 1165 thousand eggs. The larvae hatch after 4-5 days.
