Hitchhiker crab - brown with spots!

[P6R]

Hi folks
Can't find any good pics identifying this fella. Must have been in my RSM 130 for a while and spotted him a couple of days ago. Apologies for the white balance. Will try to upload a better shot ASAP. He's mostly brown with a white spotty pattern on his back.

Not hairy but has pointy claws which can't be good!!!

Any ideas if he's safe?

 

[P6R]

here you go... A better pic

 

[Oxylebius]

It is a type of Xanthid crab.
Possibly from the Atergatis floridus
- http://eol.org/pages/1021898/media
- http://species-identification.org/species.php?species_group=crabs_of_japan&id=1274

Not reef safe. If you have a sump, that would be a perfect home for it.

How long has it been in your tank? If you haven't noticed any issues w/it, you can leave it there. Eventually it may start to eat other mobile inverts and corals....

 

[P6R]

Great stuff thanks a lot. I'd been suspicious as I'd lost some discosoma (and some of the rock it was on (!) and xoas - don't know if it was this fella but he gets the blame anyway. Will read more and probably take to my lfs.

Cheers