Miles;1893902; said:Here is a pic of Nariju's Ray and StefanW rays.. both I suspect to be the "True" Argentina Histrix (This is what the original scientific data most represents).. notice the body structure and small size of maturity(12").
While there is also the "True" Histrix, which should be called Potamotrygon cf. Histrix "Rio Negro", and the "False" Peruvian Histrix..
I dont think they are the same ray at all.
The eye and spiracle structure of Nariju's ray is different then stefans and totally unique IMO.