Any idea what kind of crab this is?

Found this in the nano today while doing a water change, pic doesn't do it justice. The pic is from the back, this thing has some serious claws. I've had 2 small clowns, 2 reef chromies and a purple firefish totally disappear in the last 2 weeks. I'm hopin this is the culprit.

 

I don't know what the species is. If the claws are pointy it should be put in your sump/refugium.

It seems a little small to have killed all of those fish.

 

I think is a Mithrax crab sp.

 

Agree on some sort of Mithrax.

 

He looks like he may have destroyed the evidence but agreed with above that lil guy killing 5 fish in a week seems like a lot for it's size.

This site may help u Id him

http://www.chucksaddiction.com/hitchcrabs.html

 

So I should banish him to the sump?

 

I would, I had one like that and I didn't take any chances. I actually took mine to the LFS where it was a pufferfish's snack

 

yeah unfortunately I do not think that he is your culprit on the loss of your fish. I wouldnt leave him in my tank as when they get bigger they can eat smaller fish....but i would look at other reasons for your losses.
were these new fish to your tank? How did you acclimate them? How are your water parems?

you can put him in your sump or take him to your LFS for snack for other fish. I used to give them to my golden puffer and my peacock mantis.......so they will have a place for it

 

I had a stripey one with the exact same pattern kill a 3 inch long black perc. I watched him grab it by the tail and drag it into the rock structure. By the time I dug it out it was dead. He did appear to be mithrax species but was a bastard. Crab was only about an inch and half across at the legs too.