The beluga (Huso huso) or European sturgeon is a species of anadromous fish in the sturgeon family of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, and occasionally in the Adriatic Sea. Heavily fished for the female's valuable roe—known as beluga caviar— the beluga is a huge and late-maturing fish that can live for 118 years. The species' numbers have been greatly reduced by overfishing and poaching, prompting many governments to enact restrictions on its trade. The most similar to the Huso huso beluga is the Huso dauricus kaluga, also referred to as the "river beluga".
The beluga sturgeon is endemic to the Caspian Sea where the delicacy beluga caviar is harvested from its eggs. This has lead to their endangerment and conservation efforts have been put in place to keep this rare sturgeon alive. Generally these fish are solitary, only congregating during spawning times, during which they travel into freshwater streams. They eat a wide variety of fish as well as a few ground-dwelling invertebrates.