needlefish, common name for members of the family Belonidae, which comprises 50 species of elongated, surface-swimming predaceous fish abundant in warm seas. They have beaklike jaws armed with sharp teeth, giving them a superficial resemblance to the gar; some needlefishes reach a length of 6 ft (1.8 m). The saltwater garfish, Strongylura longirostris, may be 4 ft (1.2 m) long but is usually smaller; it is found in Atlantic coastal waters and estuaries. Garfishes resemble twigs and are often mistaken for them when lying motionless at the surface of the water. They swim in small schools and occasionally leap clear of the water in their pursuit of smaller fish. The flesh is palatable, although the greenish bones make it repellent to some. Other species include the billfish and the houndfish, or agujon, an important food fish of Puerto Rico. The closely related halfbeaks, or balaos, family Hemiramphidae, smaller than needlefishes and with only the lower jaw extended, are a herbivorous family linking the needlefishes and the flying fish. Needlefishes are classified in the phylum Chordata, subphylum Vertebrata, class Osteichthyes, order Beloniformes, family Belonidae.