South America: Brazilian Amazon and lower reaches of the Rio Tapajos, Rio Madeira and Xingu; Río Ventuari of Venezuela, southern tributaries of the Amazon from the Madeira to the mouth, and the Rios Uatumã, Trombetas, Capim, and Maranhão. One collection of what appears to be this species was also recorded from the upper Río Guaviare of Colombia.