Another crab id

[amcrambler]

My girlfriend saw this little bugger living in some of the live rock in my tank. The rock has been in for about 2 weeks now and it's a brand new tanks so he must have hitched on it. The rock has some nice nooks and crannies but I didn't realize there was a big tunnel running through one of them. I managed to scare him out by sticking a plastic spoon in one end and then I grabbed him. I think it's an emerald crab, but the colors are all wrong so I'm not sure. Same family though I believe. Figured I'd best catch him and quarrantine him until I find out what he is exactly. I found what looks to be a pic of another one like him here:

Linky

Down in the Mithrax crab section, second pic in. They don't specify what he is though. I'll attach a pic I took of him. Anybody?

 

[LeslieH]

Not an emerald which come from the tropical Atlantic/ Caribbean region. Might be a Mithrax, but definitely a xanthoid sort of crab. Sometimes the characters that put a crab into one family or another aren't obvioius. Odds are very high that it's a predator of some sort.

 

[sanfordbhines]

It does not look like an Emerald Crab to me. Emeralds do not have that much hair on their legs. Where did you get your liverock from?

I would not trust this crab in my tank.

 

[amcrambler]

Just an update on Senor Crab. My buddy had a 5 gallon he offered me so rather than execute the little bugger I took that and made myself a little predator tank. Plunked him in there and anything else I find in the big tank I'll probably toss in there with him. Got a small damsel to put in there too so that the tank doesn't look empty since the crab is always hiding in the piece of rock in there. So far they've played nice together and the crab hasn't tried eating the damsel yet.
I got the rock from a fellow on the board who was breaking down his tank. Not sure of it's origins but it's full of life and I had a small cycle as it was only out of the water for a few hours so die off was minimal. I've also got liek 10-12 black skirted scutus that came in the rocks too. They didn't come out right away but after a month or two they've been coming out of the rock crevices to eat algae. Cool little creatures. I'll have to post some pics when I get some time. Thanks for the help guys.

 

[oscarsdad608]

I found a crab like that in my tank too. He ate my snails like you wouldn't believe until I caught it. It was a fast grower and very strong. When I tried to catch it, the crabs would move rocks the size of a softball to get away.

 

[mscarpena]

Looks like a rock crab or a gorilla crab. Both can eat/knock over corals and are not good reef inhabitants.