Most starfish eat fish, pieces of shrimp, scallops, etc. You cut a piece and place it near the starfish and he will grab it climb on top of it and consume it.
Some of them eat all the garbage out of your LS..including Bristle worms, which is why alot of people dont get them..Some of them will also eat a slow or small fish, if they are hungry enough, or your inverts..
~Susie