Need ID on Small Nocturnal Crab (Photo)

[joeychitwood]

I've seen this crab which measures about 1 cm in diameter crawling on my LR at night on a couple of occasions. It first appeared about eight months after I set up the tank and LR. Do any of you know what it is? Is it safe?

 

[pnsnowboard]

thats pretty cool id try to get him out tho

 

[Lev F.]

It's a spider decorator crab. I believe they are not reef safe.

 

[JRPhd]

or a face hugger from Alien...

 

[joeychitwood]

I read about the Spider Decorator crab's habits of attaching pieces of softies and coralline to itself. So far, I've only seen the crab crawling on the coralline near the sand. I'll watch the mushrooms carefully to see if it spends time there.

 

[AdidaKev]

I'm not 100% sure, but he looks like he might be a commensal gorgonian crab. I've seen a few crabs that look very similar come in on gorgonians at my LFS. That's my best guess.

 

[Blown 346]

I myself get out all and any crabs that might be in a tank. They will eventually cause problems, it is there nature.

 

[AdidaKev]

Look familiar?

 

[joeychitwood]

Looks very close, Rachel. Do you know if it's a friend or foe?

 

[AdidaKev]

Hmm, can't seem to find much information on them. Their scientific name is Xenocarcinus conicus, but I haven't really found much as to whether or not they'll be okay in a reef aquarium. They usually live on gorgonians or hydroids, but I haven't found anything that says they pick on them or any other corals. You can never be too careful though...

Sorry I couldn't be of more help!

 

[joeychitwood]

I pulled the crab out of the tank last night. I turned on my red light and found it munching on a small snail.