This species is known only from the lower Iguazú River basin above the Iguazú Falls where it occurs predominantly in the main channel of the river but also in large tributaries (i.e. Deseado and San Antonio Rivers in the Misiones Province). It is not found in small tributaries, especially in areas without rocky bottoms. Its distributional range extends upstream of the Misiones Province into the neighboring state of Paraná, Brazil (Ref. 104794).