Class: Holostei
Body and jaws elongate; mouth with needlelike teeth; abbreviated heterocercal tail; heavy ganoid scales, about 50-65 along lateral line; dorsal fin far back, with few rays; three branchiostegal rays; interoperculum absent; two or more supratemporal bones on each side; maxilla small and immobile; supramaxilla absent; myodome absent; vomer paired; swim bladder vascularized (thus permitting aerial respiration); vertebrae opisthocoelous (anterior end convex, posterior end concave, as in some reptiles and unlike all other fish except the blenny Andamia. Maximum length about 3.0 m.
Caudal fin abbreviate heterocercal; dorsal fin base long, with about 48 rays; large median gular plate and 10-13 branchiostegal rays; swim bladder can function as a lung; no pyloric caeca. Maximum length about 90 cm.