- Source: Heliotrygon rosai
Heliotrygon rosai, or Rosa's round ray, is a species of freshwater fish in the family Potamotrygonidae. It is native to the Amazon basin (Marajó to Peru) in South America. Its maximum disc width is 80 cm (2.6 ft) and the stinger is greatly reduced, rendering it virtually harmless. It has not been evaluated by the IUCN red list.