Gars (or
garpike) are members of the
Lepisosteiformes (or
Semionotiformes), an ancient order of
ray-finned fish; fossils from this order are known from the late
Cretaceous onwards. The family
Lepisosteidae includes seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine, waters of eastern
North America,
Central America and the
Caribbean islands. Gars have elongated bodies that are heavily armored with
ganoid scales, and fronted by similarly elongated
jaws filled with long, sharp teeth. All the gars are relatively large fish, but the
alligator gar (
Atractosteus spatula) is the largest, as specimens have been recorded up to in length. Unusually, their vascularised
swim bladders can function as lungs, and most gars surface periodically to take a gulp of air. Gar flesh is edible and the hard skin and scales of gars are used by humans.