Unknown Crab

[Submarine]

I have a crab in my rock that only comes out at night. I finally caught him in the open last night. He is about an inch wide, brown and white speckled, with alternating white and brown horizontal stripes on his legs. Is he good, bad or indifferent. I have noticed my snail pop has steadily decreased over time. I also have a sally lightfoot and I have never seen him molest anything. Also what is a good website with pics to id stuff you find in your tank?
Thanks, Kevin

 

[reeflover1]

i have the same crab as a hitchhiker
never seen him bother anything
but have caught sally eating snails
and mushroom- watch the sally!!!

at my sally

 

[ragawaga]

Submarine, this sounds very much like a crab that I found hitchhiking on some rock a couple of months ago.

Here is a pic of my one

If your crab is the same one, I was told that it is a "Mud Crab" AKA Lybia Edmondsoni. It is a forager....in fact, I've only ever seen it if I've had to take the rock out of the tank for any reason.

The thread was dated May 3rd if you want to look.