''Pseudacanthicus histrix'' is a large species of

armored catfish Armoured catfish may refer to: *Family Loricariidae: The armoured suckermouth catfish, also known as suckermouth catfish, armoured catfish or simply 'plecs' or 'plecos' *Family Callichthyidae: armoured catfish, includes the genera **''Corydoras'', ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

where it occurs in the Rio Negro and lower

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

s. This species grows to a

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 ...

of . ''P. histrix'' has incredibly elongated odontodes that form a brush on the anterior margin of the pectoral fin spine in breeding males; however,

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

has not been reported for the other ''

Pseudacanthicus ''Pseudacanthicus'' is a genus of medium to large-sized suckermouth armored catfishes native to South America, where found in the Amazon and Orinoco basins, as well as rivers of the Guianas. They are primarily found in fast-flowing waters, som ...

'' species.

References

Ancistrini Fish of South America Fish of Brazil Endemic fauna of Brazil Fish described in 1840 {{Loricariidae-stub