Abstract
Claspers of four species of freshwater stingrays, which belong to the genera Dasyatis (Dasyatidae), Paratrygon and Potamotrygon (Potamotrygonidae), are examined to reveal differences in the clasper structure among these genera. The relationships of freshwater stingrays are discussed based on our examination of the clasper structures as well as that reported in recent literature for two other genera of freshwater stingrays, Himantura (Dasyatidae) and Plesiotrygon (Potamotrygonidae).
