Got some better photos of my mystery crab...

[Brie]

Actually caught the little bugger yesterday when doing a water change so managed to get a few good shots of him. Under water he has a fuzzy appearance.. Anyone have any ideas as to what he could be? He doesn't seem to harm anything.. I only ever see him scraping algae and detritus off rocks. Has grown a bit, maybe 1/3rd bigger now.

For size reference on my hand

 

[morgan]

in the bin it goes

 

[Brie]

in the bin it goes

I really dont like killing things for no good reason...

 

[Damsel13]

awwwww
bad crab??

 

[mmkeeper]

It bet he love to eat some zoo's

 

[bergzy]

i am not a big fan of killing things as well...but so far, i am not a big fan of ANY crabs. you are so lucky to have got him out without ripping your tank apart. i have been trying to get this one which is about 2 inches across the shell and just chows down big time on my sps at approximately every night at 2 am.

so...

you can kill him or let him go back in your tank and see what the little guy will do to your tank inhabitants.

 

[Mr.Firemouth]

He is a black claw Xanthid crab which could be found on Liverock from both the Caribbean and Indo-pacific regions. They are extremely fond of clams. They are naturally found near mud flats next to rock piles. Here is some more info...
http://www.tbsaltwater.com/thepackage/watchout.html
http://www.saltcorner.com/sections/guest/marineworld/Friend or Foe 8.pdf
http://www.sms.si.edu/irlfieldguide/Panope_herbst.htm

 

[Brie]

He is a black claw Xanthid crab which could be found on Liverock from both the Caribbean and Indo-pacific regions. They are extremely fond of clams. They are naturally found near mud flats next to rock piles. Here is some more info...
http://www.tbsaltwater.com/thepackage/watchout.html
http://www.saltcorner.com/sections/guest/marineworld/Friend or Foe 8.pdf
http://www.sms.si.edu/irlfieldguide/Panope_herbst.htm

Thanks Firemouth for the info.. *sigh* It does indeed seem it is a Gorilla Crab. Pewp. I really don't want to kill it.. I ended up letting it go back in the tank after taking pics, but since its in my nano I'm sure I can catch him again.

 

[Juanfer]

watch closely for any agressive behaivor, I think that if you feed him well, there will be no problem.
Good Luck

 

[Herefishyfishy]

Use it to keep the sump cleaner

 

[Snowboarda42]

Yeah I say sump it as well.

Or send it to me and I'll put it in mine (I'll pay shipping)