[Old Fr.] A long, narrow freshwater fish, the roe of which is made into caviare, and the air-bladder into isinglass. It has free gills, and its body is more or less covered with bony plates, in five longitudinal rows. The tail is heterocercal, having the vertebrae continued into the upper lobe, which is longer than the lower one, and the skeleton cartilaginous. It runs up rivers to spawn. The eggs sometimes make up nearly one-third of the fish, and there are over three million in one female. Sturgeons are found in Europe and America, and in one season 200 tons of caviare have been made on the Caspian. It is now made largely on the Delaware.