Trygon henlei Castelnau, 1855 The bigtooth river stingray or Tocantins River ray (Potamotrygon henlei) is a species of freshwater fish in the family Potamotrygonidae.

[1] This stingray is generally common and its population increased after the Tucuruí Dam was completed, unlike many other species in its range.

[1] It is replaced by the closely related P. rex in the mid and upper Tocantins basin, but that species has concentrically clustered yellow-orange spots.

[5] Compared to P. leopoldi, P. henlei is duller above, appearing blackish or dark gray-brown (as opposed to deeper black in P. leopoldi), and its underparts have a large white center and broad brownish-dusky edges (underparts mostly brownish-dusky in P.

[5][6] In episode 5 of season 3 of River Monsters, “Electric executioner”, British Scientist and Angler , Jeremy Wade[7] once hauled out a Bigtooth River stingray from a boat , The Stingray had a black body with yellow isolated spots around the disc.