Hitchicker ID please

[Lucian]

Found this little guy in the overflow, seen him hiding in the rocks the other day. I'm just wondering would he be of any harm to my hermits?!

[gobymasters]

looks like a mithrax crab its semi- aggressive so i would be very cautious.

[rambochu]

It doesn't have the right shape to be a Mithrax. It doesn't look like it's hairy, either. If I had to guess, maybe a trapezia crab? They have flat faces, smooth carapaces, and really kind of dangerous looking claws. They're harmless and live symbiotically in SPS.

I also would be surprised to hear of a small crab taking down an equivalently sized hermit.

Of course, a better picture would help a lot.

[Sugar Magnolia]

Toss it in the sump.

[Lucian]

This the best pic of it i have. I've put him back in the tank. I was just thinking that he's probably in there since i got the live rock in the tank, and i only added the hermits about three weeks ago and they all seem ok. Would have put him in the sump but i dont have one... Thanks for the feedback guys.

[GerritM]

Hi!
The pic is not good enough for an real ID, but it could be an Pachygrapsus, maybe a P. minutus.

[BEASTIEPENDENT]

Ffffffffewh, that pic is too small indeed. But from the front shape it indeed looks like a Grapsoidea (and Pachygrapsus is a genus of the family Grapsidae) and Gerrit might be right.

Do You have a reef tank or did You collect at the Atlantic Yourself?