Identify this crab???

[RoBByB]

Hi... I had bought some live rock and I found a crab that had hitchhiked in it. I had checked around looking to see what kind it is but it matches no descriptions or pictures!!! I really need help since I wanna know if it is a fish eater or algae eater before I spend money on fish!!! Can anyone help me?
Thanks,
Rob

[brody98]

Looks like a stone crab, but cant be exactly sure all crabs except maybe an emerald will go after small to very small fish If there isn’t sufficient other foods for them to feed on.

[Navy46]

Its been my experience that there is no good crab for a reef, I also get alot of little crabs in my live rock and at first they just graze the rock but as they get bigger, they will start ripping up the reef and will eat anything, including soft corals. I would get rid of it. My trick to getting them if you cant just pick them up, is to get a plastic syringe and inject boiling water into their hiding holes, this works great for mantis shrimps also. just be sure the hot water is not jetting out onto a coral though.

[brody98]

I agree for the larger crabs, I only have one emerald for bubble algae. I’ve caught them with a siphon tube over the back of the shell before but it takes patients.