yes considered a dwarf ray. max size around 14 to 16 inch, give or take.
if you look in the aqualog book you will find hummarosa varients in ther that resemble your ray alot.
if I had to guess, i would say your ray came from guyana or columbia.
its worht what any one person is willing to pay for it. retail I would say 200.00 or higher, wholesale alot less.
very nice ray, do you know what country it was imported from?