I feed them PE Mysis (sometimes Hikari, but PE are larger and according to their nutritional information are very high in protein), krill, squid, silversides, trout, shrimp, occasionally scallops. I find that they have a more vigorous feeding response if I don't get stuck too long on one food. For that reason, I try to vary it up almost every feeding. They especially like fresh food right from the seafood dept. I cut the pieces up so they are maybe the size of a peanut, no larger than say a cashew.