The bowfin Amia calva is the only living member of the family Amiidae, and part of the larger group Holostei which includes the gars.

Bowfin are easily identified by their elongate dorsal fin, which undulates when swimming.  Bowfin also possess nostril tubercles and a gular plate.  Juveniles have a yellow-ringed ocellus located in the upper portion of the caudal peduncle which is retained in adult males, but often lost or reduced to a black spot in adult females.

Amia calva is a facultative air-breather and possesses a modified gas bladder which serves as a lung.  During levels of high activity and/or low dissolved oxygen, bowfin use their lung to breathe air.