Potamotrygon histrix (Müller & Henle, 1841)
P. histrix displays winding, irregularly-shaped, light-colored splotches on a dark background. Light-brown spots with dark centers line the edge of the disc. Tail sports multiple rows of thorns. These rays have thicker bodies than many other species, and they tend to remain smaller.
Species description from Rosa (1985):
"Disc oval; dorsal surface of disc dark brown with small light spots and irregular vermiculations; disc relatively rough with sharp denticles; tail with sharp middorsal spines, in one irregular row which continues dorsally on disc as double or triple parallel rows; teeth small with tricuspid crowns, in 27 to 40 rows in upper jaw..."
A preserved specimen:
And now for some living ones!
A video of Fay Ray, my P. histrix.