Spectracanthicus murinus is a species of suckermouth armored catfish endemic to Brazil where it is found in the Tapajós River basin. This species grows to a length of SL. S. murinus appears to be unique in the sub-family Ancistrinae in that it has lost many of the traits that describe this group, such as evertible cheek plates and modified opercle. References Ancistrini Fish of South America Fish of Brazil Endemic fauna of Brazil Fish described in 1987