Beluga, European sturgeon (Huso huso), anadromous fish in the sturgeon family. Captive (image shot in a large aquarium) at Danube Delta Eco Tourism Museum Center, Tulcea, Romania. DIGITALLY CLEANED. 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. IUCN classifies the beluga as critically endangered. It is a protected species listed in appendix III of the Bern Convention, and its trade is restricted under CITES appendix II. The Mediterranean population is strongly protected under appendix II of the Bern Convention, prohibiting any intentional killing of these fish.