Body highly compressed, elongate, oval, tapers to pointed tail; small close-set eyes on left side; snout rounded; mouth small, curved, strongly so on blind side; margin of preoperculum concealed by skin and scales; dorsal origin ~ above upper eye; dorsal and anal fins confluent with the pointed caudal fin; only left pelvic fin present, 4 rays, on body midline, joined to anal fin by delicate membrane; pectoral fins absent, represented by a fine membrane; no lateral line; scales rough, on both sides of body.
A worldwide tropical to temperate genus with 66 species; represented in our area by 17 endemic species, 15 of which occur in shallow water.
