Mahury basin

Native to coastal river systems south of the Amazon delta in the states of Piauí, Maranhão, Pará, and Amapá, northeastern Brazil. It has been recorded from the rios Guamá (including tributaries such as the rio Ararandeua), Maracanã (rio Peixe-Boi), Morcego, Parnaíba, Piriá, Caeté, Turiaçu (rio Jamari), and Mearim (rio Pindaré). Reports from French Guiana and western Brazil appear to represent cases of misidentification.

This species is uncommon in the aquarium trade although its name is sometimes applied to other species. It was originally described in the monotypic genus Pseudopristella, and can be distinguished from the vaguely similar Pristella maxillaris by possession of a relatively large (vs. relatively small) humeral spot and having black pigmentation in the anal-fin restricted to the first ray (vs. a prominent distal blotch).