onio River tributary, Doce river basin. Abundance: No abundance data available. Local people mention the species as frequent but not abundant. Habitat and ecology: The stream where the specimens were found is relatively narrow, with depth varying from 0.5 to 1.5 m and has dark colored waters. Substrate is mostly sandy, with large boulders forming alternate riffles and eddy pools. Riparian vegetation is relatively well preserved. The water is slightly acid, with low nutrient concentrations. H. wheatlandii seems to be dependent on undisturbed areas, and requires special habitat conditions, mostly related to stream order, substrate features and water quality. This hypothesis can be