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.
The Gonorynchiformes are an order of ray-finned fish that includes the important food source, the milkfish, and a number of lesser-known types, both marine and freshwater.
Acestrorhynchus is a genus of 14 species of characiform fish found only in fresh water in South America, the sole genus in the family Acestrorhynchidae. Their greatest diversity is in the Orinoco and Amazon basins.
Hyphessobrycon is a genus of freshwater fish in the family Characidae. These species are among the fishes known as tetras. The genus is distributed in the Neotropical realm from southern Mexico to Río de la Plata in Argentina. Many of these species are native to South America; about six species are from Central America and a single species, H. compressus is from southern Mexico.
African tetras are a group of characiform fish exclusively found in Africa. This family contains about 18 genera and 119 species. Among the best known members are the Congo tetra, and African tigerfish.
A headstander is any of several species of South American fish, including Anostomus ternetzi, Anostomus anostomus and members of genus Chilodus from the family Chilodontidae. The name derives from their habit of swimming at a 45° angle, head pointed downwards, as if "standing on their heads".
Copella is a genus of freshwater fish belonging to the family Lebiasinidae, native to South America, known colloquially to aquarists as splashing tetras or splash tetras, because of the unique reproductive method of the best-known representative of the genus, Copella arnoldi. They are not as closely related to the tetras proper in the Characidae as initially believed.
Brycinus is a genus of ray-finned fish in the family Alestiidae. Like other "African characids", they were formerly included in the Characidae but are actually somewhat more distantly related Characiformes.
Striped headstander may refer to the fish species:
Paramormyrops is a genus of elephantfish in the family Mormyridae from Africa.
Phenacogrammus is a genus of African tetras found in Middle Africa.
Axelrodia is a genus of small characin from the Amazon Basin and Meta River in South America, with three currently described species:
Hemigrammus is a genus of freshwater fish in the family Characidae native to South America and commonly seen in the aquarium trade. These are medium-small tetras where the largest species reach up to around 11 cm (4.3 in).
Hoplocharax goethei is a species of characin endemic to Brazil where it is found in the Amazon Basin. It is the only member of its genus. It is commonly found in freshwater environments at a benthopelagic depth. This species is native to a tropical environment. This fish can reach a length of about 3 cm (1.2 in) as an unsexed male.
Iguanodectes is a genus of characin found in tropical South America, with eight currently described species:
Knodus is a genus of characins, small freshwater fish from South America.
Schultzites is a genus of freshwater fish in the family Characidae. It contains the single species Schultzites axelrodi, which is endemic to Colombia, where it is found in the upper Meta River basin.
Derhamia hoffmannorum is a species of freshwater fish endemic to Guyana, where it is found in the Mazaruni River. It is the only species in its genus. It is found in fresh water at pelagic depths in a tropical climate. The average length of an unsexed male is about 6.1 cm (2.4 in). It has an elongated body with large eyes. It is a timid species compared to other similar species such as the various pencilfish. They live near the surface of water and are known to hide whenever possible, usually under floating objects. This species only eats what can be found at the surface, as well. D. hoffmannorum will not seek food that sinks to the bottom.
Pyrrhulina is a genus of freshwater fishes found in tropical South America. Several of these species are popular aquarium fish.
Anostomus longus is small species of fish in the family Anostomidae. It is found in the upper Amazon of Peru.
