Crab ID (please?)

[Beandawg]

This is not my picture, but I have this identical crab in my tank. It must have been there for years, and I have not noticed any damage to any of my corals. I'm inclined to leave it in there, but I would love to know what it is. It is about 1 inch or so in size.

I found this thread http://www.reefcentral.com/forums/showthread.php?t=1292494
It looks like *maybe that is where this pic came from. Unfortunately, no ID was given.

 

[Calappidae]

Looks like a mithrax to me.. I'd sump it.

http://www.chucksaddiction.com/hitchcrabs.html

 

[Beandawg]

I've been looking at various mithrax and xanthid crabs for hours now, while I can't find the exact ID I'm looking for...General consensus is to remove it from the tank. I'm not going to though, not yet. I'm not really worried about my fish. If it starts munching coral, it will take a trip to the punishment sump.

 

[J2T]

From what I can see of its claws, looks like a mithrax to me. Honestly if you haven't had anything disappear and you think it has been in there awhile, I don't see the rush to drop it in the sump. No harm no foul I say. Looks pretty cool if you ask me.

 

[GerritM]

Looks like a Cyclodius sp. Primarily harmless algae eaters.