Potamotrygon adamastor

This species can be distinguished from its congeners through several characteristics, such as dark gray dorsal disc; body covered with small yellow-white ocelli with a slender dark contour; small irregular spots on disc margin (sometimes); and robust and wide tail base.^[2]The size of this tropical stingray ranges from 45 to 62 cm (18 to 24 in) disc width (DW).^[1][2]

It is endemic to a single locality of Uriracuera river, an upper branch of Rio Branco river system, Roraima, Brazil.^[1][2] This demersal species tends to inhabit the turbid wetlands with sandy sediments.^[1] The only threat to this species might be water contamination resulted from nearby illegal mining activities, as there are no records about its capture by fisheries.^[1]