Dangerous Crab?

I bought some macro for my tank today, and when I was getting ready to put it in the tank, I noticed a crab in with the macro. It's been awhile since I've read up on crabs...it sort of reminds me of an emerald crab, but it's reddish brown. The legs are hairy, and I thought I remember reading somewhere that hairy legged crabs are not good to have in your tank. I could have gotten that mixed up though. Sorry about the poor pics...he has a knack for avoiding the camera. If anyone could help me ID him, I would greatly appreciate it...a "gorilla crab" sounds familiar? Again, could just be making that up though.



another pic

pic

I'm not an expert on crabs by any means but having read a lot of crab id type threads, plus having a crab hitchhiker or two of my own I have got a better idea on what to look out for.
Looking at the size and shape of his claws the crab is to be at the very least opportunistic and as it grows could therefore pose a threat to livestock in the tank.

It's difficult to get an estimation of the size in the pics but it looks quite small at the moment. However once you put him in the tank (unless you already have) he could be extremely difficult to recapture so I would take him back to the lfs if that's where you bought the algae.

One of the gurus may be able to give you some additional information but getting a concrete id on crabs is pretty difficult.

Well, I did a bit of looking last night, and I think it is a Mithrax forceps (Red-Ridged Clinging Crab). From what I've read about them, they are like the emerald crab, just red.

Still undecided what to do with this guy...he is small..about 1/2 inch in diameter. I do have a blue spotted puffer (Canthigaster epilamprus), which means the crab could just end up as food for the puffer (he leaves my hermit crabs alone, but that doesn't guarentee he'll leave this crab alone).

Oh, decisions, decisions...

that defiantly looks like a emerald crab just red.