Otocinclus is a genus of catfish in the family Loricariidae native to South America, commonly known as "dwarf suckers" or "otos". This genus, like other loricariids, is characterized by rows of armour plating covering the body, as well as the underslung suckermouth. They are generally small in size; O. tapirape is the smallest of the species (2.4 cm), while O. flexilis is the biggest (5.5 cm). These species have adaptations that allow them to breathe air. A duct forms at the junction between the esophagus and the stomach and expands into an enlarged, ring-like diverticulum, characteristic of this genus, which allows air-breathing. Otocinclus are popular aquarium fish, and they are often purchased as algae eaters. It is difficult to breed them in captivity, and only wild caught Otocinclus are available to hobbyists. This genus is widely distributed east of the Andes of South America, throughout the lowlands from northern Venezuela to northern Argentina, but are generally absent from the Amazon and the Orinoco lowlands.
The Doradidae are a family of catfishes also known as thorny catfishes, raphael catfishes or talking catfishes. These fish are native to South America, primarily the Amazon basin and the Guianas.
Pseudancistrus is a genus of suckermouth armored catfishes native to South America.
Rineloricaria is a genus of freshwater tropical catfish belonging to the family Loricariidae. They are commonly called whiptail catfish because of the long filament that grows out of the tip of the caudal fin that is characteristic of the genus. With the exception of R. altipinnis from Panama, they are native to the rivers of northern and central South America. Some species are regularly seen in the aquarium trade.
Sorubim is a small genus of long-whiskered catfish native to tropical South America. A number of characteristics allows the differentiation of each species in the genus. Sorubim species are important food fish in South America and are highly significant to fisheries of some areas; however, harvests of these fish are not identified as much as other, more popular food fishes such as Colossoma, Arapaima, and Brachyplatystoma. Some species of this family are popular aquarium fish.
Scoloplax is the only genus in the catfish family Scoloplacidae, the spiny dwarf catfishes.
Farlowella is a genus of fish in the family Loricariidae native to South America. This genus is broadly distributed in Amazon, Orinoco, Paraná and coastal rivers of the Guyana Shield. It is absent from the Pacific slope of the Andes and from the coastal rivers of the Brazilian Shield. Many of these species are kept in aquariums. This genus has a unique body shape that resembles a thin stick of wood. The body is slender and elongate, often with a pronounced rostrum and a brownish color with two lateral dark stripes beginning at the tip of the rostrum, passing over the eyes and ending at the tail, which are periodically interrupted on the caudal peduncle.
Harttia is a genus of armored catfishes native to South America.
Parotocinclus is a genus of fish in the family Loricariidae native to South America. This genus is distributed through almost all hydrographic systems in South America from the Guyana Shield drainages and Amazon Shield tributaries to the coastal drainages of eastern and southeastern Brazil, including the rio São Francisco basin. Most species have the caudal peduncle oval in cross section. It has been found that Characidium species may interact with P. maculicauda. The small Characidium will follow grazing P. maculicauda, which release particulate matter dislodged from the catfish's foraging.
Pareiorhina is a genus of armored catfishes native to South America where they are only found in Brazil. These species are known to occur at altitudes above 650 metres (2100 ft) in various rivers of the Grande, Paraíba do Sul, São Francisco and Tietê River basins. This genus was first erected by Gosline in 1947 as a monotypic genus to include Rhinelepis rudolphi. It was not until 2003 that a second species, P. carrancas, was described. The third species, P. brachyrhyncha was described in 2005. Pareiorhina forms a monophyletic subunit with Neoplecostomus within the subfamily Neoplecostominae.
Plectrochilus is a genus of pencil catfishes native to South America.
Pseudostegophilus is a genus of pencil catfishes native to rivers in tropical South America. The members of this genus are obligate parasites that feed on scales and mucus of other fish.
Parastegophilus is a genus of pencil catfishes native to South America.
Schultzichthys is a genus of pencil catfishes native to South America.
Stegophilus is a genus of pencil catfishes native to South America.
Pygidianops is a genus of pencil catfishes native to South America.
Typhlobelus is a genus of pencil catfishes native to South America.
Henonemus is a genus of pencil catfishes native to South America.
Ituglanis is a genus of small freshwater fish in the family Trichomycteridae native to South America. Their greatest diversity seems to occur in the Amazon River basin. Most species inhabit leaf litter, with several species living in caves.
Auchenipterus is a genus of driftwood catfishes.
