Teleostei

Teleostei, whose members are known as teleosts, is by far the largest group of ray-finned fishes, class Actinopterygii, and holds 96 percent of all living fish species. It is variously considered a division or an infraclass in different taxonomic systems and includes over 26,000 species arranged in about 40 orders and 448 families. Teleosts range from giant oarfish measuring 7.6 metres or more, and ocean sunfish weighing over two tonnes, to the minute male anglerfish Photocorynus spiniceps, just 6.2 millimetres long. They differ from other bony fish mainly in the jaw bones: a movable premaxilla and matching jaw muscles let them protrude the jaws to grab prey and draw it into the mouth. The upper and lower lobes of the tail fin are about equal in size, and the spine ends at the caudal peduncle. Teleosts are economically important as food, sport and aquarium fish and as research animals in genetics and developmental biology.