Elongate, fusiform body; head pointed; flattened between eyes; mouth not protractile, large, lower jaw projecting ; teeth minute, no canines; no teeth on roof of mouth; tail deeply forked with pointed tips; dorsal X, 10-11; anal III, 8; last rays of dorsal and anal fins filamentous; pectoral long, 15-16 rays; lateral line scales 65-75; dorsal and anal scaleless.
Purplish-brown above, blue-grey below, a silver sheen over body; edges of preopercle and opercle black.
Size: 70 cm.
Habitat: inshore rocky and coral reefs.
Depth: 5-70 m.
Indo-Pacific; resident at Cocos in the eastern Pacific; also at Malpelo Is.