#ray-finned

Primitive ray-finned fishes: Orders Polypteriformes, Acipenseriformes, Lepisosteiformes, Amiiformes

Fish categorized into these orders are among the least advanced of all bony fishes. The orders above correspond, respectively, to bichirs, sturgeons and paddlefish, gars, and the bowfin (a species with its own order). These fishes have skeletons composed of both bone and cartilage, and most are freshwater species, though some can live in both fresh and saltwater. All species of primitive ray-finned fish live in the northern hemisphere and are some of the largest freshwater fish in the world (sturgeons can reach lengths of up to 8 m).

Shown: Ornate bichir (Polypterus ornatippinus) American paddlefish (Polyodon spathula) Longnose gar (Leipsosteus osseus) Bowfin (Amia calva)