BLUE SHARK (Prionace glauca)

Recognition: The blue shark has a snout longer than the width of the mouth, very long pectoral fins about as long as from the tip of the snout to the last gill slit, the midpoint of the first dorsal fin base closer te thc pelvic fin origin than to the pectoral axil, and weak keels on the caudal peduncle.

Color: Color is dark indigo blue on top, shading to bright blue with metallic hues on the sides. The undersides are white. The blue color changes to dark gray soon after death.

Size: Usual size is 180-240 cm (71-94 in). The largest on record measured 383 cm (12.6 ft). It is said to grow much larger.

Similar species: The shortfin mako has a similar blue color but differs in having a conical snout and long smooth-edged teeth.

Biology: This is probably the most common large shark in the open oceans. It is cosmopolitan in tropical, subtropical, and temperate waters. Off North America, it ranges from Newfoundland to Florida and the Gulf of Mexico. It inhabits clear, deep blue waters where the depth is greater than 182 m (I OC fathoms. seldom venturing near land, except in clear deep water around islands.

Economic importance: In spite of its abundance, the blue shark is of little economic importance because both its flesh and fins are of poor quality.

Fishing: It is often taken in tuna longline operations.

Carcass: Blue shark carcasses are very seldom landed because they have very little, if any commercial value. The carcass is relatively long and thin, blackish blue in color, and has very week keels on the caudal peduncle. References