by B. B. Collette
Elongate compressed fishes. Scales small and cycloid. Mouth large with many fine teeth in bands. Adult males develop a bony crest on front of head. Lateral line curved upward above pectoral fin. Dorsal and anal fins very long, continuing almost to caudal fin, without sharp spines or finlets; dorsal fin origin on nape; anal fin origin at or before midpoint of body; pelvic fins fitting into a groove on body; caudal fin deeply forked, without any keels on fin or caudal peduncle. Back a brilliant metallic blue-green in life, fading rapidly to yellowish.
Epipelagic in most warm seas.
Recent revision: Gibbs & Collette (1959).