South America: Orinoco basin in Venezuela and Colombia; rio Branco drainage in Guyana and Brazil, as well as in the upper rio Negro near the mouth of the rio Branco, but is not known from elsewhere in the Amazon system, or in the Guianas
Definition: length from the tip of the snout to the tip of the longer lobe of the caudal fin, usually measured with the lobes compressed along the midline. It is a straight-line measure, not measured over the curve of the body
