I have a 9" male flower ray. he eats chopped canadian night crawlers, and blackworms, live ghost shrimp, and frozen ghost shrimp (occasionally). I want to get him on ANYTING else, but particularly krill, silversides, supermarket shrimp, and smelts. Any ideas on how i can get him to switch? he is in a tank all by himself and is a good eater (on what he likes). i never had any problems with my motoros... they learned to eat everything right away. any and all advice would be much appreciated!! thanks!