Astyanax is a genus of freshwater fish in the family Characidae of the order Characiformes. Some of these fish, like many of their relatives, are kept as aquarium pets and known collectively as tetras. With around 150 described species and new ones being described yearly, this genus is among the largest of the entire order; Hyphessobrycon also has more than 145 species and which one is larger at any one time depends on whether more species have been recently described in one or the other. The blind and colorless cave tetra of Mexico is a famous member of the genus, but its taxonomic position is disputed: Some recognize it as part of the Mexican tetra and this is supported by phylogenetic evidence, but others recognize the cave form as a separate species, A. jordani.
Leporinus is a genus of fish in the family Anostomidae native to South America. The fossil species Leporinus scalabrinii, known from the late Miocene of Entre Ríos in Argentina, has only recently been added to this genus after being misidentified as a species of primate under the name Arrhinolemur scalabrinii for over 100 years.
Carl Henry Eigenmann was a German-American ichthyologist of the late nineteenth and early twentieth centuries, who, along with his wife Rosa Smith Eigenmann, and his zoology students is credited with identifying and describing for the first time 195 genera containing nearly 600 species of fishes of North America and South America. Especially notable among his published papers are his studies of the freshwater fishes of South America, the evolution and systematics of South American fishes, and for his analysis of degenerative evolution based on his studies of blind cave fishes found in parts of North America and in Cuba. His most notable works are The American Characidae (1917–1929) and A revision of the South American Nematognathi or cat-fishes (1890), in addition to numerous published papers such as "Cave Vertebrates of North America, a study of degenerative evolution" (1909) and "The fresh-water fishes of Patagonia and an examination of the Archiplata-Archelenis theory" (1909).
Astroblepus is a genus of fish in the family Astroblepidae found in South America and Panama. This genus is the only member of its family. These catfishes are primarily found in torrential streams in the Andean area. Astroblepus pholeter and A. riberae are troglobites adapted to living in subterranean water systems. These species are typically small, less than 10 cm (4 in). The largest species reaches 30 cm (1 ft). These fish have suckermouths like those of loricariids. They have two pairs of barbels, maxillary and nasal. The dorsal fin spine lacks a locking mechanism. These fish also have odontodes, tiny teeth on their skin. All species exhibit a conical, pointy type on their fin rays like that found in other loricarioids; other species also exhibit a blunt type that is only found on their skin.
Hisonotus is a genus of armored catfishes native to South America. Species of Hisonotus and Curculionichthys are the only representatives of the subfamily Otothyrinae having serrae on the posterior edge of the pectoral fin spine. These species are small fishes, generally found in small fast flowing streams, where they grasp to the branches and leaves of aquatic or subaquatic plants. The species of this genus mostly occur in Atlantic coastal streams of southern Brazil and the Paraguay-Paraná system of southern South America. They are also distributed in the Río de La Plata basin and coastal rivers of southeastern Brazil.
Cheirodon is a genus of characins occurring in South America. Of the 10 currently described species; one, C. jaguaribensis, is placed here as a convenience, as its actual position in Characidae is unknown.
Pimelodella is a genus of three-barbeled catfishes.
Pseudoplatystoma fasciatum or barred sorubim or barred catfish is a species of long-whiskered catfish native to the Suriname, Corantijn and Essequibo. The nocturnal predator feeds mainly on other fish and crabs. Females reach a more notable size. They become sexually mature at 56 cm (22 in), males at 45 cm (18 in) and this species reaches a maximum length of 90 cm (35 in) TL. Fecundity seems to be estimated at 8 million eggs per kg, but was recently measured in aquaculture at a lower, and more likely number of 150,000 eggs laid per kg.
Chasmocranus is a genus of three-barbeled catfishes native to South America.
Trachelyopterus is a genus of driftwood catfishes
Brachyglanis is a genus of Three-barbeled catfishes native to South America.
Chaetostoma, also known as the bristlemouth catfish, is a genus of suckermouth armored catfishes native to South America with one species, C. fischeri, extending into Panama. Most species inhabit flowing rivers in the lower Andes and its foothills. Some species are kept in unheated aquaria.
Moenkhausia is a genus of freshwater fish in the family Characidae native to tropical and subtropical South America. These are medium-sized tetras where the largest species only reach around 12 cm (4.7 in).
Aphyocharax is a genus of characins from South America, specifically the Amazon, Orinoco, Essequibo, Paraguay and Paraná basins. The 11 currently described species in this genus are:
Jupiaba is a genus of characins from South America. with 27 currently described species:
Curimatella is a genus of toothless characins from South America, with five currently described species:
Psectrogaster is a genus of toothless characins from South America, with these currently described species:
Steindachnerina is a genus of toothless characins from South America, with 24 currently described species:
Dolichancistrus is a genus of suckermouth armored catfishes native to South America.
Iguanodectidae is a family of freshwater fish in the order Characiformes that lives in South America. It is home to the subfamily Iguanodectinae and the monotypic Bryconops clade. Several species in the family, such as the green line lizard tetra, the tailspot tetra, and the orangefin tetra, are sometimes taken as aquarium fish.
