Hi, new to the group. I got a elegance coral frag from my lfs. It was the best frag available as the others looked poor. After tank introduction I spotted a critter and removed it. I just found another one I think they have killed it now. Please help ID it and advise if there will be more or did both come in/on the coral and that's why the other frags were closed up etc. Is it a gall crab?