Please help identify crab

[SamIAm]

Looks similar but not exactly the same as a crab in an earlier thread. Please help identify and let me know if it is reef safe. It's body is about a 1/2 inch in diameter. I munches on algae, but has broken off pieces of the live rock.

Thanks.

 

[Atari]

It's the same as the one in the other thread.

 

[quarryshark]

Looks like you got some cool hitchhickers.
I got a bunch of crabs on my rock last week. Havn't seen them since putting them in.