51380 Anostomoides atrianalis Pellegrin, 1909 Anostomidae Headstanders Characiformes Teleostei South America: Río Orinoco basin in Venezuela, in the Essequibo River basin in Guyana, and in the Amazon basin, including Madeira, Negro, Tocantins and Xingu rivers, in Bolivia, Brazil, Colombia, and Peru. AMNH 39717 Anostomoides atrianalis