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.
Hisonotus aky, sometimes known as the green hisonotus, is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in Argentina's Uruguay River basin. It reaches 4 cm SL. It was formerly considered a member of the genus Epactionotus, although it was transferred to Hisonotus in 2009.
Hisonotus armatus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Lagoa dos Patos basin in Brazil. The species is found in slow and moderate-flowing waters over sandy substrates with submerged or marginal vegetation. It reaches 6 cm in total length and is noted to be sympatric with the species Hisonotus laevior throughout its distribution.
Hisonotus laevior is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Lagoa dos Patos system, ranging from Lagoon Mirim to the Jacuí River basin. It is found in slow to moderate-flowing waters with sandy substrate and submerged vegetation. The species reaches 7.5 cm in total length.
Hisonotus carreiro is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Taquari River drainage basin and the Lagoa dos Patos system in Brazil. The species reaches 3.6 cm SL.
Hisonotus charrua is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Uruguay River and the mouth of the Río de la Plata in Uruguay. The species may be found in both freshwater and brackish environments and reaches 3.6 cm SL.
Hisonotus chromodontus is a species of catfish in the family Loricariidae. It is native to Brazil, where it occurs in the Tapajós basin. The species is usually found in shallow flat parts of creeks with clear water, low current, and sandy substrate. It reaches 3.3 cm SL.
Hisonotus depressicauda is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Tietê River basin. The species reaches 5 cm SL.
Hisonotus depressinotus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Tietê River basin. The species reaches 3 cm SL. It is not to be confused with the related species Hisonotus depressicauda, which has a similar name and is found in the same river basin.
Hisonotus francirochai is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Grande River basin. The species reaches 3.6 cm SL.
Hisonotus leucofrenatus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Ribeira de Iguape River basin. The species reaches 6 cm SL.
Hisonotus maculipinnis is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the basins of the Río de la Plata, the Paraguay River, and the Paraná River. The species reaches 4 cm SL.
Hisonotus megaloplax is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the drainage basin of the Passo Fundo River, which is a tributary of the Uruguay River. It reaches 4.7 cm SL.
Hisonotus nigricauda is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the basins of the Paraguay River and the Paraná River. It reaches 6 cm in total length.
Hisonotus notopagos is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Camaquã River drainage and the Lagoa dos Patos system in Brazil. The species reaches 3.7 cm SL.
Hisonotus pachysarkos is a species of catfish in the family Loricariidae. It is a freshwater species native to Brazil, where it occurs in the Ivaí River basin in the upper Paraná River system. It reaches 4.15 cm SL and was described in 2016 by Cláudio Henrique Zawadzki and Weferson Júnio da Graça of State University of Maringá and Fábio F. Roxo of São Paulo State University. FishBase does not list this species.
Hisonotus paulinus is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Tietê River basin. The species reaches 4 cm SL.
Hisonotus prata is a species of catfish in the family Loricariidae. It is a freshwater species native to South America, where it occurs in the Taquari River drainage and the Lagoa dos Patos system. It reaches 3.3 cm SL.
Hisonotus taimensis is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Lagoon Mirim drainage. The species reaches 6.6 cm SL.
Hisonotus devidei is a species of catfish in the family Loricariidae. It is a freshwater species native to South America, where it occurs in the Pandeiros River, a tributary of the São Francisco River. The species was described in 2018 by F. F. Roxo, G. S. C. Silva, and B. F. Melo on the basis of morphology and patterning, as it differs from other members of the genus Hisonotus by the presence of distinctive dark blotches. FishBase does not list this species.
