Genus: Prionace, Blue Shark

PRIONACE

BLUE SHARK

Body very elongate and fusiform; snout long and narrowly rounded; no spiracles; eyes round, with nictitating membrane; teeth serrated, long and triangular, broader and curved on top jaw, center tooth of top jaw very large; five gill slits, last two over pectoral; gill arches with papillae along front edge; 1st dorsal fin low, its origin well behind pectoral fins, center of base nearer pelvics than rear insertion of pectorals; no ridge between dorsals; pectorals very long, narrow, slightly curved, pointed tips; tail base with small keel; tail fin strongly asymmetrical, lower lobe of tail well developed, upper lobe with undulating ridge along its top edge, and a notch under its tip, pits at its base.

The single species in this genus occurs worldwide in tropical and temperate seas.