Mystery Crab

[Imbarrie]

Can anyone help me ID this crab?

It was introduced to my tank from some daisy coral from LFS.
The Daisy came from a tank with many different corals.

I have a 12g aquapod with soft corals and mushrooms.

Do I have an immediate worry with leaving this guy in the tank for a while?

It lives in a hollow caved out piece of fiji rock that would be impossible to get him out and there is little room to set up a trap. When I upgrade I will probably try to trap him and place him in a fuge/sump.

Attached are some pictures from the last molt.

 

[FocusReefing]

Gorilla crab. Hes bad news for reefs...

 

[Imbarrie]

Are all gorilla crabs hairy?

This guy is smooth.

Is this an IMMEDIATE danger? Or, are they only dangerous when they get a certain size?

The only reason I ask is this guy is going to be tough to get out of the tank.

 

[FocusReefing]

Im not an expert but I think they get more hairy the older they get. I have one in my 24 nano that Ive been to lazy to remove. He hasnt done any damage to anything that Im aware of. And hes about the size of a quarter. But look into it more and wait to see what others have to say. I could be wrong. Good luck.

 

[Imbarrie]

He is very shy and almost never comes all the way out, if at all.
I wont see him for weeks, then when I do see him its only a limb coming out of a crevice.

I dont think he has caused any damage yet.
But I do feed well.

As soon as I can I will be moving him to a more appropriate area.

 

[nyccat1]

It looks like an Emerald Mithrax Crab. If it's not already hairy, it will as it gets older. Grows up to about 2 1/2", I have one in my tank also. With all my live rock I left him alone too. Very interesting to watch at night. He does not cause any harm, but make sure there is ample food in the tank. He is a excellent scavenger, and algae eater. They hide mostly during the day in caves and are nocturnal. If not enough food to scavenge it my eat small fish, inverts, and corals. Some people prefer them, some people don't.

 

[Imbarrie]

no, that does not any emerald mithrax i havbe run into.

I do have one of those. Green and small and the hind part is hairy.

 

[mr_X]

it's a xanthid crab. not reef safe.
http://www.chucksaddiction.com/hitchcrabs.html

second row, first pic. there's your boy!

 

[Imbarrie]

Well,
He is out of the tank, that is the important part.
Unfortunately I only had a limited amount of time to get him out and he really didnt want to come out.
He ended up coming out in pieces.

Better for the community.

Thank you,

 

[fernandokng]

that is a disturbing picture of a horse in your avatar