I found a crab in my tank that must of hitchhiked on the piece of rock I bought a few weeks ago. I took it out and put in QT tank because I found it on my coral and now it seems to be dying. Do crabs kill corals? Also does anyone know of a good web site that has pics of crabs? I've been searching the web but no luck so far. I'll post a pic tomarrow if it's still alive.