Acropora crab?

[GratefulReef]

So, I got a nice acro yesterday from the divers den, and being the nosy reef keeper I am I was checking out the tank tonight with a small flashlight. I looked at my acro and saw a little crab claw poking out, I know there are acropora crabs but dont know much about them. Anything I should be worried about, or is it safe? I only have 4-5 hermit crabs in my tank so its not something old.

 

[lionfish300]

I have two that living in my pocillico acro, every now and then you can see them stick their claws out try to grab food going by

 

[smtank]

More times than I can count I have received SPS with acropora crabs residing within.

Never have they caused an issue, and I was consider them a lucky find.

 

[Daimyo68]

I have acro crabs in almost every colony. I am lucky to have a buddy who owns a shop, and before we dip new arrivals, we check for acro crabs and remove them (since they won't survive the dip). I always bring them home, or put them back onto an acro at his store.

Here's a video of one I got some time ago. He was on this acro when I got it, and he's pretty big now. Just for size ref, the harlequin shimp was roughly 3.5 inches at the time. The acro crab was swinging at the Harlequin while protecting his acro colony.

<iframe width="560" height="315" src="http://www.youtube.com/embed/QcekwMYTE9s" frameborder="0" allowfullscreen></iframe>

 

[papa_jerry]

There are also the bad crabs with the blue eyes that eat at the arcos

 

[Sever]

I had one in my acropora, one with blue eyes and " hairy" body. It was a bad crab. His food is tissue of acro. So beware of this one

 

[GratefulReef]

I dont think it has blue eyes, I usually only see his claws which are redish pink and the part of the body I could see was creamy colored tho I dont remember if it was hairy. Thanks for the warning.

 

[myaerica]

I have been to live aquarias facility quite A few times and would say most of there colonies have crabs living in them. when they quarantine the corals they take the crabs out, then put them back in when the corals when they are done with the dips they use.

 

[biggles]

Your description sounds like it's a typical commensal crab and a great little bonus. They are fiercely protective of their colonies and help keep them clean and tidy. Look up Trapezia sp. and Tetralia sp. and you should be able to get a better idea of which one it is. Btw, any small hairy crab with bands on the legs found in a colony is best innoculated with 1ml of 'don'teatmyspsitus' which renders them very SPS safe. You can return them to the colony after the injection as they tend to be way less active after the 'procedure'......... this guy was eating pocil polyps but hasn't touched one since the 'vaccination'. :thumbsup: