Ancistrus caucanus is a species of catfish in the family Loricariidae. It is native to South America, where it was at one point thought to occur in the Cauca River basin in Colombia, for which it is named, although subsequent research suggested in 2013 that it is actually native to the Magdalena River basin, whereas its congener Ancistrus vericaucanus is the species native to the Cauca. The species reaches 5.2 cm SL. It is not to be confused with the similarly named species Lasiancistrus caucanus.
Ancistrus bolivianus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the basins of the Beni River, the Mamoré River, and the Madre de Dios River. The species reaches 8.8 cm SL.
Ancistrus aguaboensis is a species of catfish in the family Loricariidae. It is native to South America, where it is known from the upper Tocantins River basin. The area in which the species occurs is characterized by riffles and a primarily rocky substrate, although some amounts of gravel and sand are present. The species reaches 6.7 cm SL. It sometimes appears in the aquarium trade, where it is usually either known as the Aguaboa ancistrus, the Aguaboa pleco, or by its L-number, L032.
Ancistrus minutus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in tributaries of the Tocantins River upstream of the Serra da Mesa Dam in Goiás, Brazil. The species reaches 5.7 cm SL. It is named for its notably small size when compared with many of its congeners.
Ancistrus formoso is a species of catfish in the family Loricariidae. It is native to South America, where it occurs only in the cave of Buraco do Ducho in the Formoso phreatic system in Brazil. It is a stygobitic species that is known to lack eyes and body pigmentation, which indicate a high level of specialization to living in a subterranean, lightless environment. It is one of three known stygobitic members of Ancistrus, alongside A. cryptophthalmus and A. galani. The species reaches 7.9 cm SL.
Ancistrus erinaceus is a species of catfish in the family Loricariidae. It is native to South America, where it is reportedly known from Chile. The species reaches 7.5 cm SL.
Ancistrus nudiceps is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Takutu River basin in the upper Branco River drainage in Guyana. The species reaches 7.9 cm SL.
Ancistrus occidentalis is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Bobonaza River basin in Ecuador. The species reaches 8.6 cm SL.
Ancistrus montanus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in high-altitude freshwater environments, with the type specimen being collected from an elevation of around 457 m, in the Beni River basin in the upper Madeira River drainage in Bolivia. The species reaches 9.2 cm SL.
Ancistrus bufonius is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Apurímac River basin in Peru. The species reaches 11.5 cm SL.
Ancistrus brevifilis is a species of catfish in the family Loricariidae. It is a freshwater fish native to South America, where it occurs in the Tuy River basin in Venezuela. The species reaches 11.8 cm SL.
Ancistrus brevipinnis is a species of catfish in the family Loricariidae. It is a freshwater fish native to South America, where it occurs in the Lagoa dos Patos basin in Brazil. The species reaches 10.7 cm SL.
Ancistrus cuiabae is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Cuiabá River basin, which is part of the Paraguay River drainage in Brazil. The species reaches 11.5 cm SL.
Ancistrus damasceni is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the upper Parnaíba River basin in Brazil. The species reaches 6.5 cm SL.
Ancistrus dubius is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the basins of the Amazon River, the Paraná River, and the Paraguay River. The species reaches 12.6 cm SL.
Ancistrus eustictus is a species of catfish in the family Loricariidae. It is a freshwater fish native to South America, where it occurs in the Baudó River basin in Colombia. The species reaches 18 cm SL and it is known to inhabit high-altitude areas, with the holotype being reportedly collected from a location approximately 914 m (3000 ft) above sea level.
Ancistrus maracasae is a species of catfish in the family Loricariidae. It is a freshwater fish native to the Caribbean, where it occurs in the basin of the Maracas River, which is a major tributary of the Caroni River in Trinidad and Tobago, indicating that it is endemic to the island of Trinidad. The species reaches 8.3 cm SL.
Ancistrus megalostomus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Beni River basin, which is part of the Madeira River drainage in Bolivia. The species reaches 8.3 cm SL and is noted to inhabit high-altitude environments.
Ancistrus piriformis is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Acaray River basin, which is part of the Paraná River drainage in Paraguay, although it has also been reported from Argentina. The species reaches 8.3 cm SL.
Ancistrus taunayi is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Uruguay River basin. The species reaches 11.9 cm SL and at least 52.3 g in weight.
