Color dark blue on top, brown-blue laterally, silvery white underbelly; upper jaw elongated in for of spear; first dorsal greatly enlarged in the form of a sail, with many black spots, its front squared off, highest at midpoint; pelvic fins very narrow, reaching almost to the anus; body covered with imbedded scales, blunt at end; lateral line curved over pectoral, then straight to base of tail.

OFFSHORE species, in south Florida associated with waters near Gulf Stream; off the panhandle near the 100-fathom line.

Common to 7 feet.

Rapid growing species, reaching 4 to 5 feet in a single year; swims at speeds up to 50 knots; feeds on the surface or at mid-depths on smaller pelagic fish and squid.