Seriously though, In my opinion, it is a Peruvian Motoro Variant.. I have imported a number of rays that were similiar, but didn't have that kind of marbling.
Here is a "Common" ray we imported from Peru.. Motoro sp. "Peru" or Motoro sp. "Common".. They are a common brown ray that infests the beaches all over the amazon, they cost exporters about $7USD.. inflation due to shipping from their on out..
All these rays came from Peru, too.. They were all imported as 'Raya Common', or Common Stingray. I still think they are just peruvian Motoro variants, as I have seen 4 or 5 different patterns come from these 'common' or un-ID'ed rays..