Ostariophysi

Catfish are a diverse group of ray-finned fish of the order Siluriformes (historically Nematognathi). Catfish are named for their prominent barbels, which resemble a cat's whiskers, though not all catfish have prominent barbels. All Siluriformes lack scales, instead possessing either smooth skin or armour-plated bodies. This order of fish are defined by features of the skull (such as maxillae modified into the barbels' bases) and swimbladder. Catfish range in size and behavior from the three largest species alive, the Mekong giant catfish from Southeast Asia, the wels catfish of Eurasia, and t

Cypriniformes is an order of ray-finned fish which contains many sister families and genera of cypriniform fish split into several suborders, including the barbs, loaches, botias, carps, danionins, and minnows, amongst others. Cypriniformes is an "order-within-an-order", placed under the superorder Ostariophysi—which is also made up of cyprinid, ostariophysin fishes. The order contains 11–12 families (with some authorities having listed as many as 23), over 400 genera, and more than 4,250 named species; new species are regularly described, and new genera are recognized frequently. Cyprinids ar

Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, more than 2000 different species are described, including the well-known piranha and tetras. Characins are most diverse in the Neotropics, where they are found in lakes and rivers throughout most of South and Central America. At least 209 species of characins are found in Africa, including the distichodontids, citharinids, alestids, and hepsetids. The rest of the characins originate in the Americas.

Ostariophysi is the second-largest superorder of fish. Members of this superorder are called ostariophysians. This diverse group contains 10,758 species, about 28% of known fish species in the world and 68% of freshwater species, and are present on all continents except Antarctica. They have a number of common characteristics such as an alarm substance and a Weberian apparatus. Members of this group include fish important to people for food, sport, the aquarium industry, and research.