''Hypostomus commersoni'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

in the family Loricariidae. It is native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

, where it occurs in the

Paraná River The Paraná River ( es, Río Paraná, links=no , pt, Rio Paraná, gn, Ysyry Parana) is a river in south-central South America, running through Brazil, Paraguay, and Argentina for some ."Parana River". Encyclopædia Britannica. Encyclopædia Br ...

drainage, including the

Iguazu River __NOTOC__ The Iguazu River ( pt, Rio Iguaçu, br , es, Río Iguazú} ), also called Rio Iguassu, is a river in Brazil and Argentina. It is an important tributary of the Paraná River. The Iguazu River is long, with a drainage basin of . Cou ...

, the

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in ...

, the Río de la Plata, and the Dulce River. It is typically found in rivers with muddy substrates and moderate currents. The water that ''H. commersoni'' inhabits usually has a temperature of 16.8 to 27.8 °C (62.2 to 82.0 °F), a pH of 7.2 to 9.2, a

turbidity Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can ...

of 23.7 to 442 NTU, an

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

concentration of 6.1 to 9.1 mg/L, and a conductivity of 1.087 to 2.654

μS A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is equal to 1000 ...

/cm. ''H. commersoni'' reaches 60.5 cm (23.8 inches) in

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

and can reportedly weigh at least 1.8 kg (4 lbs). It appears in the aquarium trade, where it is often known as Commerson's pleco.

References

{{Taxonbar, from=Q521854 commersoni Fish described in 1836 Taxa named by Achille Valenciennes Fish of South America