Reptile & Amphibian Forums

He came in with a live rock order at the store I work at and we have no idea what he is. We have kept him because we don't want to sell him to someone until we know what he is and what he will get along with. Right now he is in the tank with the fiddler crabs but over the last couple of days the fiddlers have been turning up with missing legs and he is getting bigger. He is about and inch wide, very dark purple, almost has a velvety look to him, and very big thick claws (not long claws, the stubby ones like emerald crabs have). He stays tucked under a piece of live rock that is in the tank. He isn't skittish or aggresive, when I do water changes I can actually pet him and he doesn't move. Any info would be great.

http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm might be able to help you ID the crab. If you find out what it is, please let us know.