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 a historical one, but scientists today tend to prefer "characids" to reflect their status as a, by and large, monophyletic group. To arrive there, this family has undergone much systematic and taxonomic change. Among those fishes remaining in the Characidae currently 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 in several regions, and also constitute a large percentage of captive freshwater aquarium fish species.
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.
Hepsetus odoe, the African pike characin, is a predatory freshwater characin belonging to the family Hepsetidae. It was formerly considered that there was a single species of Hepsetus pike characin but recent studies have led to the species being split and Hepsetus odoesensu stricto is the west African representative of the group.
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.
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.
Piabucus is a genus of freshwater tetras in the family Iguanodectidae. All three species are found in South America, largely the Amazon and its major tributaries. None of them are longer than half a foot long, with the largest reaching a maximum size of 12.9 cm (5.1 in), and they are slender, with relatively deep chests and long pectoral fins. Their scales are pale or silvery, with lateral lines that stand out.
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 the genus Mesoborus. It reaches up to 25 cm (9.8 in) in standard length. It is a specialized fish-eater. Mesoborus crocodilus hunts by waiting motionless at the surface and then charges at prey. the species is listed as least concern when it should be listed as data sufficient due to only 172 sightings. Mesoborus crocodilus is often referred to as the crocodile tetra though is not official.
Nannocharax is a genus of distichodontid freshwater fishes found in Africa.
Phago is a genus of distichodontid freshwater fishes in tropical West and Middle Africa. They grow 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 which sometimes eat insects and whole fish.
Iguanodectinae is a subfamily of small freshwater fish in the family Iguanodectidae. They are most prominently found in the Amazon river basin and its major tributaries, but they are also known from the Tocantins, Orinoco, and Paraguay rivers. It has two genera, Piabucus and Iguanodectes. Some species in the subfamily are taken from the wild for aquariums, like the red- and green-line lizard tetras. There is minor, but ongoing, debate regarding its taxonomy.
Bryconops melanurus, sometimes called the tail-light tetra, is a small species of freshwater fish from South America that primarily preys on insects. It lives in small schools and is an active swimmer, which means that it requires open space in its habitat. Nonetheless, it does not demonstrate a strong preference for any one biotope within its native range.
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.
