; subclass Actinopterygii, order Atheriniformes)
A large family of marine and freshwater fish, all of which have streamlined bodies and spineless fins. The single dorsal and anal fins are set far back on the body, close to the forked tail fin. Typically, all flying fish have greatly expanded pectoral fins, the tips of which may extend to the tail base. One of the more widely distributed species is the cosmopolitan Exocoetus volitans (flying fish), reaching a length of 25 cm. The halfbeaks have no expanded pectoral fins, but can be recognized by the elongated lower jaw, which in several species is at least three times the length of the upper jaw. The lower jaw is thought to scoop up minute animals as the halfbeak skims along the surface. One of the largest species, Hemirhamphus far, may reach 60 cm. There are about 108 species, distributed world-wide.
Subjects: Zoology and Animal Sciences.