Huso

Huso is a genus of large sturgeon in the family Acipenseridae. The best known species is Huso huso, the beluga sturgeon, famed for producing the highly valued beluga caviar. The genus name is used in various classifications, although some authorities place these species in the genus Acipenser.

Huso huso is native to the Caspian and Black Sea basins of Europe and western Asia, and historically ranged into the Danube and other large rivers. A closely related species, Huso dauricus, occurs in the Amur River basin in eastern Russia and parts of northeast Asia.

These are among the largest freshwater fishes, capable of long migrations. Adults inhabit marine or brackish waters and enter rivers to spawn, while juveniles spend the early years in rivers. Maturity is late, and females produce large numbers of eggs. Diet consists of benthic fishes and invertebrates on the riverbed.

For centuries their roe has been harvested for caviar, driving dramatic declines in wild populations. The species is listed as endangered on the IUCN Red List; trade in beluga caviar is regulated under CITES Appendix II. Conservation efforts include aquaculture, restocking, and habitat protection to reduce pressure on wild stocks.

In taxonomic practice, two widely recognized species are Huso huso and Huso dauricus; some classifications place these species in the genus Acipenser.