Crab Identity

[mrguppy]

I just started a 20G reef aquarium 1 week ago. It contains 20 lbs of Fiji liv rock, and 15 lbs crushed coral. Green hairy mushrooms and yellow polyps.
Yesterday I noticed this hitch-hiker. Any ideas of what it is? And, is it "reef safe"?

 

[Betta132]

Can you get a better picture of the claws? That will help with identification.

 

[mrguppy]

picture with claws

picture with claws

Attached are two pictures displaying crabs claws. It is a little bigger than a quarter.

 

[Calappidae]

IMO looks like a regular mithrax crab (emerald)

eats algae.

 

[Noah 123]

IMO looks like a regular mithrax crab (emerald)

eats algae.

That's what I thought too. It's got the same claws, face, and looks like the color of an emerald crab.

 

[Betta132]

Yep- I'll go with emerald as well.
They're algae eaters, but like any non-porcelain crab they're opportunistic. If they're very hungry or something is sick, they are capable of killing and eating tankmates.