Mithrax eating acro!

[WWWD]

so i have this fairly large purple mithrax crab that hitched in on some corals a while back. i am not entirly thrilled about having him but he has never caused much damage before. tonight i busted him with a pretty good sized hunk of blue tipped acro in his claw munching away on it. has anyone else ever had an issue with this kinda thing before. damn im ****ed off. i really don't want to empty my reef out to get this guy out.