Molecular Markers Reveal a New and Possibly Threatened Species of (Poeciliidae, Cnesterodontini) from the Upper Paraná River Basin, Brazil.

comprises 10 valid species occurring in the major river basins of South America. Recent ichthyofaunistic studies in the Ivaí River basin, upper Paraná River system, suggested the existence of a possible new species, which was identified as sp. based on morphological characters.