What is is crab?

[itsamyheff]

I noticed some tissue loss on a acro colony and found this guy hanging out at the base of a branch. Kinda looks like a emarld but not so sure. What you guys think.
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[frantz]

Not an Emerald, probably one of many Acro eating crabs based on where you found him. Very few hitch hiker crabs are desirable in the reef tank.

 

[itsamyheff]

I looked up some of the bad guys and found some similar to but most are hairy looking crabs. I hate to take him out if he is not a bad guy, BUT, where I found him and seeing damage, I can only think he is the culprit. I guess he could always go to the sump.

 

[nassar0505]

hmm always thought acro crabs were all good, but I guess if you see damage eat him :}

 

[john_shay]

I had this problem once, they look almost exactly like the acropora crab, but they are hairy, i actually intentionally added him, then saw that he was actually killing polyps on the acro, he went in the sump, only one way out of there and its not in one piece

 

[ralph atl]

I have a few acro crabs, love 'em!

 

[reeferman]

thats an acro eating crab,usually they have blue eyes but not always.the good commensal crabs have smooth shells and a band over their eyes like a visor.

 

[itsamyheff]

this one is not smooth at all. I have another acro crab (white smooth and with the band). He doesn't seem to bother anything. Looks like he is going to the sump.