Species (Xiphias gladius) of prized food and game fish, found in warm and temperate oceans worldwide. A slender, scaleless fish, it has a tall dorsal fin and a long extension of the snout, used for slashing at prey. The sword is flat, rather than rounded as in marlins. The swordfish is also distinguished by its lack of teeth and pelvic fins. It is purplish or bluish above, silvery below, and grows as large as 15 ft (4.5 m) and 1,000 lb (450 kg). Though a popular food fish, it may have dangerous levels of mercury concentrated in its flesh.