You where right it was a heater burn. Shes doing well now and switched over to raw fish and shrimp. If anyone has something similar and are new to the hobby these pictures should assure you that you need the heater covers before you put the fish in the tank. I waited two days before buying the cover and learned the hard way that rays skin is very sensitive. I was worried at fist but after doing 20% water changes for a few days and her appetite hasn't gone down instead shes been eating more everyday I don't think theres anything to worry about.i consider myself lucky plenty of other people have had there ray get infected and die due to burns from the heater.