What is the difference between orbignyi and humerosa? I noticed the rays have spiny top of their tails where the tail meets body, if that helps identifying them 
andersp90;1596164; said:Sp. peru may max out at 32" disk size.. Take a look (4th pic):
http://www.freshwaterstingray.nl/Frames%20Engels/English.html
Hmmm.. you cant link to the different pages in franks homepage.. -.-
Take a look at species 5, pic 4.