Acipenser is a genus of fish that includes sturgeon, one of the largest freshwater fish in the world. There are many synonyms for the word acipenser, including the Latin name for the fish, Acipenseridae. Other synonyms for acipenser include beluga, sterlet, ossetra, kaluga, and sevruga, all of which are species of sturgeon. The names of these species may vary depending on their location and origin. For example, the beluga sturgeon is found in the Caspian and Black Seas, while the sterlet sturgeon is native to the Danube and Volga rivers. Regardless of their name, all species of acipenser are highly sought-after for their caviar and as food.