Need a crab ID without a good picture

[SPotter]

So I bought 10 emerald crabs (or so I thought) from reefcleaners.org about two months ago. They seemed a little darker in color when I put them in but didn't question it any further. Well now two months later I see a couple of them and they are so dark they look black and have extremely hairy legs. I've taking pictures but because my back and bottom panels are black I can't get a good shot of their body's. My fear is they're some kind of a gorilla crab. My zoas have been slowly and systematically disappearing lately. Here's the best picture I can get so far.....

 

[SPotter]

Was able to pluck these guys....

 

[Calappidae]

Look like regular emeralds to me.

 

[peasofme]

regular emeralds with hairy legs

 

[Betta132]

It's quite possible they're eating your zooanthids if they're hungry. Emerald crabs are usually considered safe because they usually eat alage, but if they're hungry they'll eat anything that can't get away from them. This is a crab thing, pretty much every crab in the world will do that.

 

[KeystoneAq]

+1 Emerald crabs mine are identical

 

[Crooked Reef]

I say emeralds as well. If you want to be sure look inside their elbow joints. They should be red.