Body stout, cylindrical; head short, rounded between eyes; forehead profile convex; no groove on nape; snout short, conical; eyes small, mouth small, ventral; teeth sharply triangular; gill openings - 5, short, last 2 over pectoral base; first dorsal large, ~ midway between pectorals and pelvics; second dorsal and anal very small; pectorals, very long, narrow, curved, with pointed tip; pelvics large; tail not lunate, upper lobe extremely long, ~ equal to body length, fin very thin, small lobe at tip of long lobe about 2x length of 2nd dorsal fin base; no keels on tail base.
Back and under snout brown, grey, blue or blackish; belly abruptly white, this color extending onto flank above pectoral fin; pectoral fin tip with white dot.
Size: > 600 cm.
Habitat: oceanic, pelagic.
Depth: 0-550 m.
Circumtropical; Canada to Chile and throughout our region.