Mantis Shrimp Food?

[krissyfish20]

Hi!
I recently found a small mantis shrimp in my tank (about 1 inch). I luckily got him out and now he's living in a small tank of his own with some live rock. I would like to keep him since he's rather cute, but I'm not sure what he will eat. I've been feeding him invertebrate pellets and he seems to gobble these up fast, but I don't know if it's good enough. Should I be feeding him frozen brine shrimp or mysis as well? And how often should I be feeding this guy? I know he's a tank pest but I really don't want to get rid of him for now, and don't want to be starving him.
Thanks