Bolivian Freshwater Stingrays (Potamotrygonidae): Species Characterization and Taxonomic Knowledge Update

The aim of this study was to characterize the species of stingrays present in Bolivia and to update the species list. Forty–four specimens were examined, and 32 linear measurements were taken on each individual. Specimens examined are deposited in the Ichthyological Collection Universidad Mayor de San Simón–Museo d’Orbigny, Cochabamba, Bolivia. Eight species and two genera Paratrygon and Potamotrygon were identified. The Amazon Basin comprises seven species and La Plata Basin four. The sub–basins with the highest species diversity were Mamoré and Iténez. The species with the widest distribution was P. motoro. Some species, such as P. amandae, P. motoro and P. pantanensis share certain diagnostic morphological characters, making their identification difficult. A dichotomous artificial key for species identification is provided. This study reveals an increase in the number of stingrays species previously documented in Bolivia.