crab hitchhiker. good? or bad?

can someone identify what crab is this. i am not familiar with crabs. i just spotted this crab on one of the sps i bought and was wondering if this is a good or a bad crab for my reef tank.

 

It's fine. It's a trapezia pocillopora crab. Beneficial I think.

 

Yeah, it's an acro crab. Commensal to many SPS colonies in the wild. Definitely beneficial to large colonies.

 

thanks for the quick replies FaceOfDeceit and Evolved.
that's what i thought since i found it on an acro. he will be back with it's acro host.

evolved. finally pulled the trigger on the rhomboid wrasse by the site you sent me. thanks for that. love the new guy but very shy

 

Saw that in the other thread; figured that was where you acquired them both. He'll come around in time. Any trouble with the flames?

 

I bought a colony last week and it has one that lives in their. It hasent hurt it. I believe they are good.

 

nope, they're all getting along.
now only if i have a lineatus

 

Trapezia Pocillopora/Acropora Crab I do believe is correct.

I know this was pretty well concluded yesterday but I figured if anyone was interested in a study on the benefits of these guys check out:

research by University of California, Santa Barbara