Claspers in chondrichthyans are specialized elongations on the posterior side of the pelvic fins of males that are used for sperm transfer during copulation. The aim of this study was the description and characterization of the external morphology and skeletal components of the pelvic fin clasper of Potamotrygon motoro (Batoidea: Potamotrygonidae). The study included three juvenile specimens (2 males and 1 female) and two adult specimens (1 male and 1 female) from the Paraná River, Corrientes Capital. The samples were fixed in 10% formalin and processed using the diaphanization technique. The material was preserved in glycerol for observation. Macroscopically, sexual dimorphism is evident in males, through a structure in the posterior region called a clasper, with a slightly tapered conical shape, visible dorsally and ventrally. In diaphanous samples, the posterior cartilaginous element...