There are 27 species that belong to the sturgeon family. Virtually unchanged for 200 million years, Sturgeon are true living dinosaurs that can reach upwards of 15 feet in length and weigh up to 1800 pounds.
Several species of sturgeon are harvested to produce caviar. Sturgeon are smooth-skinned and don't have scales.
Famous sturgeon species are beluga, white sturgeon (A. transmontanus) and Siberian sturgeon (A. baerii).