I bought a reticulated stingray about a week and a half ago in the tank in the store they looked very healthy and seemed to be taken care of very well. My water parameters are right and i am doing bi weekly water changes. My problem is that i cant get him to eat i have tried to feed him earth worms as well as blood worms and black worms he seemed to chew on the blood worms a little but then would swim off and leave them alone, but now he just keeps swimming around against the flow of the filter and against the glass and doesn't stop long enough to eat. Does anyone have any ideas whats wrong? Please help.