Two signs of a predatory crab...one large pincer and/or hairs/fuzz...looks like you got both. As far as crabs eating snails, if they can, and they're hungry, they will.
Just guessing from the claws.But it could be an emerald crab,which is fairly safe as far as crabs go.
Notice how the tips are cup shaped.Thats for getting hold of algae and pulling it loose from the rock.
Thanks, I looked up some images of emerald crabs and that looks more like it than anything else. I really doubt it's a predator type crab seeing as I never see it out in the open and it only comes out at night.
just cause it doesnt come out in the day or in the open, doesnt mean its not predator. all the crabs i know of like to hide except for the porcelain crab i have.
LOL
I was ready to lynch one of my snails since I thought it was knocking over one of my coral frags all the time, turns out I had it in the crab hole so the crab was moving it every night!
The best pic I can come up with so far, trying to poke him with a stick so he'd come out.
It looks like he has white feet., but the rest is mostly greensih.
I can't see anything in that pick but I think Yotes right, that arm could be an emerald crab and they are safe in your tank. All I can tell you is that if its a predatory crab you need to remove it asap as one of the crabs in my tank has just destroyed everything in less then a week.