Crab ID?

[dnh]

I have a 30 gallon tank I bought from a neighbor. I have had it running for about two weeks with few problems, other than the fact that the previous owner though aiptasia looked nice.
I just found a crab I can't identify after searching the board for several nights. He is all black with red eyes, and he is about two inches wide and one inch tall. He is nocturnal and he has a smooth shell and legs.
Any help would be greatly appreciated.

 

[townsdp]

Check out the thread "got a pic of this sucker" in the reef tank board. It has a bunch of people (including myself) talking about those creepy crabs.

 

[dnh]

Thanks townsdp! That is him! I sure hope someone gets a good ID on them so we can do some good research on their specifics.