- A large sturgeon, Acipenser sturio, which can grow to 60 kg and is found in the Caspian Sea, Black Sea, Mediterranean and the western Atlantic. It has a firm white to pink flesh which may be baked, grilled or smoked. The roe, which may amount to up to 22 kg from a single female, is processed into caviar mainly in Russia and Iran. The Atlantic sturgeon is now only found in the Gironde estuary and is currently an endangered species. Captive breeding is being attempted.