dark purple hairy crab
 

I just discovered this dark purple almost black very hairy crab. It has delicate hook shaped pinchers on it, not claw like. I noticed it eating little bits off the live rock. Is this a bad crab? and if so how to I get it out. It moved very fast.

If it is snacking on your rock wait till it gets bigger and decides to trim your sps'

I've got bigger problems now. Was watching this hairy crab last night eat every bit of crud off of the live rock and discovered serveral other larger crabs. I just set up this tank last week and am in the cycling process. I have to get these things out. Any ideas How.

Get us a picture so someone can make a positive ID. That way you will know if they are reef safe or not

Setup a bottle trap to gather them up for ID.

could you please tell me how to do that. Should I use a raw shrimp from the grocery store for bait? Thanks