I have always loved watching my crabs clean rock, and they never seem to bother anything. All I read about on RC is how there are no "good crabs". I ended up catching and turning in 2 Red Mithrax, and 1 BIG Emerald for credit at a LFS because I don't want to wake up one morning to chomped corals. Is this myth or fact? I still have one gorilla in hiding that I hope to catch. The only ones I will keep in there are my porcelains.