The bowfins are an order (Amiiformes) of primitive ray-finned fish. Only one species, the bowfin Amia calva, family Amiidae, exists today, although additional species in six families are known from Jurassic and Cretaceous fossils.
The most distinctive characteristic of the bowfin is its very long dorsal fin consisting of 45 to 50 rays, and running from mid-back to the base of the tail. The caudal fin is a single lobe. They can grow up to 1 meter in length, and weigh 7 kg.
Bowfins are found throughout eastern North America, typically in slow-moving backwaters. When the oxygen level is low (as often happens in still waters), the bowfin can rise to the surface and gulp air into its swim bladder, which is lined with blood vessels and can serve as a sort of lung.
They are nocturnal feeders, eating a variety of invertebrates (insects, crayfish) and vertebrates (frogs, fishes).