My advice on what to feed mantis shrimp has always been a varied diet rich in crab, shrimp and shell fish available in many fish markets (clams, scallops, mussels). We also find that pile worms work well. I prefer live food, but frozen shrimp (whole if possible) work. For are smaller animals (under 3") we also use live adult brine shrimp. A soak in a nutrient such as Selco seems to help.
Recently we have been experimenting with other commercially available foods. The one that seems to work best, at least a supplement, is freeze dried krill (Jumbo whole). Our stomatopods love them, their color is returning, and they are easy to use and not terribly expensive (I bought enough for several hundred of feedigs for about $30). I feed a 5' O. scyllarus one, 1 inch krill a day and that seems adequate. The krill float when dry, but when given directly to the animal, they seem to have no trouble eating the entire krill. Be careful not to over feed, however. They break apart and disperse throughout the tank making them hard to remove.
Roy
