Sturgeon is name by which we recognize the main species of fish in the family with the latin name Acipenseridae, The term includes over 20 species and several closely related species that have distinct common names, notably sterlet, kaluga, and beluga. Collectively, the family is also known as the true sturgeons. The two best-known genera are Acipenser, and Huso. Caviar is roe of the sturgeon fish. The four best loved caviar are Beluga, Sterlet, Ossetra, and Sevruga.