Source : Webster's Revised Unabridged Dictionary (1913)

Sterlet \Ster"let\, n. [Russ. sterliade.] (Zo["o]l.)
   A small sturgeon ({Acipenser ruthenus}) found in the Caspian
   Sea and its rivers, and highly esteemed for its flavor. The
   finest caviare is made from its roe.