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.
Characidae, the characids or characins is a family of freshwater subtropical and tropical fish, belonging to the order Characiformes. The name "characins" is the historical one, but scientists today tend to prefer "characids" to reflect their status as a by and large monophyletic group at family rank. To arrive there, this family has undergone much systematic and taxonomic change. Among those fishes that remain in the Characidae for the time being are the tetras, comprising the very similar genera Hemigrammus and Hyphessobrycon, as well as a few related forms such as the cave and neon tetras. Fish of this family are important as food and also include popular aquarium fish species.
Cypriniformes is an order of ray-finned fish, including the carps, minnows, loaches, and relatives. Cypriniformes is an Order within the Superorder Ostariophysi consisting of "Carp-like" Ostariophysins. This order contains 11-12 families, although some authorities have designated as many as 23, over 400 genera, and more than 4,250 species, with new species being described every few months or so, and new genera being recognized frequently. They are most diverse in southeastern Asia, and are entirely absent from Australia and South America. At 112 years old, the longest-lived cypriniform fish documented is the bigmouth buffalo.
A piranha or piraña is one of a number of freshwater fish in the family Serrasalmidae, or the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes. These fish inhabit South American rivers, floodplains, lakes and reservoirs. Although often described as extremely predatory and mainly feeding on fish, their dietary habits vary extensively, and they will also take plant material, leading to their classification as omnivorous.
The Anostomidae are a family of ray-finned fishes that belong to the order Characiformes. Closely related to the Chilodontidae and formerly included with them, the Anostomidae contain about 150 described species. Commonly known as anostomids, they are found in freshwater habitats from the Río Atrato in northernmost South America to warm-temperate central Argentina; they are of Amazon origin, with few found west of the Andes. Their scientific name approximately means "mouth on top", from Ancient Greek áno- (ἄνω) "up" + stóma (στόμᾶ) "mouth", in reference to the arrangement of these fishes' mouth opening.
Lepidophagy is a specialised feeding behaviour in fish that involves eating the scales of other fish. Lepidophagy is widespread, having evolved independently in at least five freshwater families and seven marine families. A related feeding behavior among fish is pterygophagy: feeding on the fins of other fish.
The redbreast tilapia is a species of fish in the family Cichlidae. It is found widely in the southern half of Africa. Its natural habitats are freshwater lakes and freshwater marshes. It is known as the redbreast kurper in South Africa.
Apteronotus is a genus of weakly electric knifefish in the family Apteronotidae, distinguished by the presence of a tiny tail fin. This genus is restricted to tropical and subtropical South America and Panama where found in a wide range of freshwater habitats. They feed on small animals.
Chalceus is a genus of fish that inhabits freshwater habitats in South America. Members can be found in the Amazon and Orinoco basins, as well as in the Guianas and various tributaries of the former. It is the sole representative of the family Chalceidae.
Myloplus is a genus of freshwater fish in the family Serrasalmidae found in tropical and subtropical South America, where they inhabit rivers and streams. They are primarily herbivores, but also take some animal matter. Depending on the exact species, they reach up to 16–56 cm (0.5–1.8 ft) in standard length. Adult males have a double-lobed anal fin and filamentous extensions on the dorsal fin, and both sexes can be brightly colored when breeding.
Belonophago is a small genus of distichodontid freshwater fish found in Middle Africa. They are specialized fin-eaters.
Eugnathichthys is a genus of distichodontid fishes found in the Congo basin in Africa. They are specialized predators that feed on the fins of other fish.
Hemigrammocharax is a genus of distichodontid fishes found in Africa, with these currently recognized species:
Monostichodus is a genus of fish in the family Distichodontidae found in tropical Africa.
Ichthyborus is a genus of distichodontid fishes found in tropical Africa. They are piscivores that feed both on (whole) fish and fins of fish.
Mesoborus crocodilus is a species of distichodontid fish found in the Congo River Basin in Middle Africa. It is the only member of its genus. It reaches up to 25 cm (9.8 in) in standard length. It is a specialized fish-eater.
Nannocharax is a genus of distichodontid freshwater fishes found in Africa.
Phago is a genus of distichodontid freshwater fishes found in tropical West and Middle Africa. They reach up to 17 cm (6.7 in) in total length, are slender in their overall shape and have a beak-like snout. They are specialized fin-eaters, but may on occasion also feed on insects and (whole) fish.
Bryconops munduruku is a small freshwater fish of the family Iguanodectidae that lives in the rivers of South America. Its adipose fin is black, with a clear base, and it has two humeral spots, which is a feature it shares with few congeners. Its fins are a variety of yellow, red, black, and clear, and mature males have hooks on select fin-rays.
Piabucus caudomaculatus is a small freshwater fish inhabiting the rivers of South America. It was the first member of the family Iguanodectidae to be reported from Bolivia, and it remains endemic to the region, found solely in the Mamoré river basin. It displays a preference for slow-moving waterways and has a largely insectivorous diet.
