Pseudacanthicus histrix is a large species of armored catfish endemic to Brazil where it occurs in the Rio Negro and lower Amazon basins. This species grows to a total length 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 has not been reported for the other Pseudacanthicus species. References Ancistrini Fish of South America Fish of Brazil Endemic fauna of Brazil Fish described in 1840