what do asterina starfish eat?

[Brighteyes_13]

just wondering if anyone can verify what i think im seeing in my tank... ive been having troubles regrowing my GSP since my accident this spring and have been finding less and less of it in my tank... for the last few days ive noticed one of those small asterina starfish looking kinda suspicious in my GSP. i was under the impression that asterinas only eat dead/decaying stuff but it really looks like a path has been mowed right through the polyp mat right where he is (purple mat, showing grey of rock in a nice, clean quarter inch path about an inch long).


any ideas whats going on?!