Crab ID help, please...

[SurlyT]

Saw this in my tank about 6 weeks after adding some new live rock. Think it might be a type of mithrax crab, but haven't seen an exact match for it anywhere so far. The legs are yellowish brown, slightly striated and very hairy. The shell and claws are nearly jet black (though they appear slightly purple here because I gamma-filtered the picture to enhance viewability).

I don't know if I could catch him if I wanted to (have only seen him again once since the original sighting), but I have to ask the usual question - good or bad? If bad, to what other tankmates? And just how bad?

Thanks in advance for any help.

 

[saltycreefer]

Had one like that in a tank at my old job, didn't bother anything and got quite large, about 3''.

 

[yiliyang]

That is a ruby crab, similar to a green emerald crab. I have one in my tank, just pick at my rocks all day.

Yili

 

[mallyk]

That looks almost exact to the crab that I seen the other day in my tank.

I posted a thread on it, but didn't have a camera.

 

[JackKerouac]

in my LFS there is a tank with a couple of these crabs I never seen them doing bad guys and aslo the LFS owner told me they are good ones