Crab ID please?

[rocket]

I don't know if this is the right forum to ask this question but here goes.
I have a 75g tank running for about 4 months and it has 65lbs of LR. Anyway a couple weeks ago I noticed a strange looking molt of a crab leg. The only crabs I know we have are the regular blue leg hermits and they aren't very big yet and this foreign leg I saw was much bigger and red. At that time I just figured that it might have fallen out of some LR. But tonight I found the molted shell on the sand so now I'm wondering what are the chances that i have a live crab in my tank? Does anyone recognize this kind of crab? Is it "safe"? Could it be killing fish?
I have been keeping a very close eye on the tank (even in the middle of the night) and Ive never seen any trace of this crab.
Thank for your help!
Nathan

 

[matts125]

looks like an emerald crab or maybe just some kind of rock crab and they can sneak up on fish at night and can even kill them especially small ones. however some people love these crabs in their tank as great scavengers. I my self have had bad luck with them eating my corals...

when I find these I put them in my refugium...

Matt

 

[Reefdaddy1]

Stick it in your sump or Fuge. It wouldnt hurt.

 

[rocket]

How do I find it? My wife and I are both scouring the rocks and caves. Can we lure him out or trap him?

 

[mmkeeper]

Try using a flashlight when the lights are out. He might not like the bright lights.