The Hypoptopomatinae are a subfamily of catfishes of the family Loricariidae, composed of 17 genera and approximately 80 species. This subfamily represents about one-tenth of all loricariid species.
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.
Parotocinclus adamanteus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Paraguaçu River basin in the state of Bahia in Brazil. A phylogenetic analysis reportedly indicates that P. adamanteus is most closely related to three other species in the genus Parotocinclus: P. jequi, P. prata, and P. robustus. The species was first described in 2019 by Edson H. L. Pereira, Alexandre Clistenes de A. Santos, Mário C. C. de Pinna, and Roberto E. Reis. FishBase does not list this species.
Parotocinclus amazonensis is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Amazon River basin in areas with a pH of 6.0 to 7.0 and a dH range of 5 to 15. The species reaches 2.5 cm in total length.
Parotocinclus arandai is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in tributaries of the Jucurucu River and the Buranhém River in Brazil. It is found in clear shallow waters with a depth of around 0.3 m (0.98 ft) and a substrate of sand or gravel. The species reaches 4.3 cm SL.
Parotocinclus jequi is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the headwaters of the Jequitinhonha River basin in Brazil. It is found in areas with clear water, marginal vegetation, a substrate of rocks or pebbles, and a depth of 0.3 to 1.2 m. The species reaches 5.4 cm SL.
Parotocinclus prata is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Da Prata River, which is part of the São Francisco River basin in Brazil. It is most often found either in clear creeks, surrounded by dense forest, with a substrate of rocks, pebbles, sand and occasionally leaf litter, or in larger water bodies with scarce marginal vegetation and an exclusively sandy substrate. The species is known to feed on cyanobacteria, diatoms, green algae, and other organic matter. It reaches 5 cm SL.
Parotocinclus robustus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the São Francisco River basin in Brazil. It is found in shallow rivers with slow to moderate flow speed, a depth of 0.4 to 1.5 m, mostly clear water, and a mixed substrate consisting of stones, gravel, sand, and occasionally mud. The environments inhabited by this species usually have marginal vegetation, which the fish is often found in association with. The species reaches 4.2 cm SL.
Parotocinclus bidentatus is a species of catfish in the family Loricariidae. It is a freshwater species native to South America, where it occurs in the Paraíba do Sul basin in Brazil. The species reaches 3.8 cm SL.
Parotocinclus collinsae is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Essequibo River basin. The species reaches 5 cm SL.
Parotocinclus cristatus is a species of catfish in the family Loricariidae. It is native to South America, where it is known from coastal rivers near Ilhéus in the state of Bahia in Brazil. The species reaches 4 centimeters (1.6 in) in total length.
Parotocinclus dani is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in tributaries of the Tapajós basin in Brazil.
Parotocinclus doceanus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Doce River basin. The species reaches 4.4 cm SL.
Parotocinclus halbothi is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Trombetas River basin in Brazil, as well as the Maroni basin in Suriname. The type locality of the species is a shallow, clear, unvegetated stream with a mixed substrate composed of gravel, sand, and leaf litter, though the fish is reported to be most frequently seen in portions of the stream with a gravel substrate. This species is noted to coexist with a variety of other fishes in its environment, including the genera Aequidens, Apistogramma, Bryconops, Callichthys, Copella, Erythrinus, Gymnorhamphichthys, Helogenes, Hoplias, Laimosemion, Mastiglanis, Pyrrhulina, and Synbranchus. It reaches 2 cm SL.
Parotocinclus haroldoi is a species of catfish in the family Loricariidae. It is native to South America, where it is known from the state of Piauí in Brazil, with a 2020 redescription defining its range as the Parnaíba River basin. The species reaches 3.5 cm SL.
Parotocinclus cabessadecuia is a species of catfish in the family Loricariidae. It is a freshwater species native to South America, where it occurs in the Parnaíba River basin of Brazil, alongside its congeners Parotocinclus haroldoi and Parotocinclus cearensis. The species reaches at least 3.32 cm SL. It was described in 2017 by T. P. Ramos, S. M. Lima, and R. T. Ramos. FishBase does not list this species.
Parotocinclus jacumirim is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Jacuípe River basin in Bahia, Brazil. The species reaches at least 5.07 cm SL and was described in 2020 by Dario Ernesto da Silva-Junior, Telton Pedro Anselmo Ramos, and Angela Maria Zanata based on fin morphology, dentition, and differences in plate coverage on the snout and abdomen. FishBase does not list this species.
Parotocinclus muriaensis is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Paraíba do Sul basin in Brazil. The species reaches 3.1 cm SL.
Parotocinclus seridoensis is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the upper basin of the Piranhas River in Brazil. The specific epithet of this species, seridoensis, refers to the Caatinga ecoregion of Brazil where the species is found, which is reportedly locally known as "Sertão do Seridó". The species reaches 4.3 cm SL.
Parotocinclus variola is a species of catfish in the family Loricariidae. It is native to South America, where it reportedly occurs in a blackwater creek known as Quebrada Tacana, which is a tributary of the Amazon River in Colombia. The species inhabits sandy areas and reaches 2.9 cm SL.
