Gar, large, slender, thick-scaled, predatory fish of family Lepisosteidae, order Semionotiformes, class Actinopterygii. Gars are found in fresh waters of eastern N America, Central America and Cuba, occasionally in brackish water and, rarely, in the sea. The 7 living species are divided into 2 genera (Lepisosteus and Atractosteus) by some ichthyologists; others consider them all as Lepisosteus. In Canada, 2 species, the rare spotted gar (L. oculatus) and the more familiar longnose gar (L. osseus), reach their northern limit in the Great Lakes drainage basin.
Gars are characterized by diamond-shaped scales and a long snout with needlelike teeth. The gas-bladder, cellular and richly supplied with blood vessels, acts as a lung, enabling gars to breath air in stagnant waters. Gars may reach 183 cm long and 22 years of age.
They feed principally on other fishes, which they seize by a darting movement from cover of vegetation. A sideways swipe of the snout impales prey crosswise on their teeth.
Gar flesh is edible but not attractive. The eggs are poisonous to mammals and birds. The importance of gars as predators of economically important fishes is uncertain, but large gars can destroy gear set for other fishes.