I could only imagine. I had two 6 inch pbass and they ate like crazy. I could only imagine big ones like yours. I bet a 18" pbass could eat 1/2 lb of shrimp. I shipped the pbass out and only do dats and gars now.
Can you see the transparent tube in the right of the tank, which transports the rays food directly under a stone plate, where the rays are already waiting.....