Huso huso
FAMILY
Acipenseridae
TAXONOMY
Huso huso Linnaeus, 1758, Danube and rivers of Russia.
OTHER COMMON NAMES
English: European sturgeon, great sturgeon.
PHYSICAL CHARACTERISTICS
The beluga sturgeon is the largest sturgeon species. It has been recorded to attain a length of 28.2 ft (8.6 m) and weight of 2,866 lb (1,300 kg), although such large specimens are rare. The body is gray or dark green in color with lighter sides and a white belly.
DISTRIBUTION
Beluga sturgeons occur in the Black, Caspian, and Adriatic Seas and in most of their tributaries.
HABITAT
This species inhabits nearshore areas of seas and large channels of rivers.
BEHAVIOR
Adult beluga sturgeons live at sea for most of the year but migrate up large river tributaries for spawning. The fry, or young fish, move downstream from rivers to the sea immediately after hatching.
FEEDING ECOLOGY AND DIET
Juvenile beluga sturgeons feed on benthic invertebrates, such as mollusks, worms, and crustaceans; adults eat other fishes.
REPRODUCTIVE BIOLOGY
Beluga sturgeons mature slowly and are extremely long lived (up to 150 years). Sexual maturity occurs around 14 years of age for males and 18 years for females. Females may produce over seven million eggs, but reproduction only occurs once every five to seven years. Beluga sturgeons spawn in late spring by scattering eggs and sperm in the water over rocky substrates.
CONSERVATION STATUS
The beluga sturgeon is listed as Endangered on the IUCN Red List. It may be extinct in the Adriatic Sea, and populations have declined throughout its range. The Caspian population is made up largely of fish from stocking programs.
SIGNIFICANCE TO HUMANS
Beluga sturgeons are valued throughout the world as the source of superior caviar. The caviar commands high prices, and the market demand has driven fisheries in eastern Europe to continue exploitation despite severe population declines.
