ABSTRACT
Needlefishes are a relatively small family of beloniform fishes (Rosen & Parenti 1981) which differ from other members of the order in having both upper and lower jaws extended into long beaks filled with sharp teeth (except in the neotenic South American freshwater genus Belonion). The nostrils lie in a pit anterior to eyes. There are no spines in the fins. The dorsal, with 11-43 rays, and anal fins, with 12-39 rays, are posterior in position; the pelvic fins, with 6 soft rays, are located in an abdominal position; and the pectoral fins are short, with 5-15 rays. The lateral line runs down from the pectoral fin origin (except in Ablennes and some freshwater genera) and then along the ventral margin of the body. The scales are small, cycloid, and easily detached. Precaudal vertebrae number 33-65, caudal vertebrae 19-41, and total vertebrae 52-97. Some freshwater needlefishes reach only 6 or 7 cm in total length while some marine species may attain 2 m.
