''Sturisoma nigrirostrum'' is a species of armored catfish

endemic Endemism is the state of a species being found only 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 foun ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, where it is found in the

Ucayali River The Ucayali River (, ) is the main headstream of the Amazon River. It rises about north of Lake Titicaca, in the Arequipa region of Peru and becomes the Amazon at the confluence of the Marañón river, Marañón close to Nauta city. The city of ...

basin. This species inhabits gently to swiftly flowing white waters, typically in areas with abundant submerged wood in the main river flow. It grows to a length of .

Sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

is evident, with hypertrophied

odontode Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They consist of a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to t ...

s on the sides of the male's head.

References

* Sturisoma Fish of South America Freshwater fish of Peru Fish described in 1940 {{Loricariinae-stub