Hitchhiker Crab ID

[Quantum Aquaria]

So I've noticed something moving inside my liverock lately and finally, it was out and about and I caught it

 

Based on link below, looks to either be a Xanthidae type Crab or a Mithrax type Crab. Either way, I don't think it's a good thing to have in my tank. It's seperated now until I can determine what to do with it... based on the picture, anyone have an idea of what it is and whether it's reef safe or not?

 

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

 

[steveoutlaw]

Gorilla Crab - Get rid of it!

[Chad]

sump monster!!

[Quantum Aquaria]

that would explain the 2 RBTAs I got are all of a sudden missing. oh well... at least I'm glad i caught him. Thanks...

Gorilla Crab - Get rid of it!

[extreme_tooth_decay]

that would explain the 2 RBTAs I got are all of a sudden missing. oh well... at least I'm glad i caught him. Thanks...

 

ummm...no it wouldn't?

[Integral9]

The last hitchhiker crab I got looked very similar to that and dragged my brand new LTA into a rock and ate it. I had to split the rock open to get him out / try to save the LTA. I say you feed him to a mantis.

[davelin315]

The pointy and serrated claws point towards a bad crab. Feeding habits can be determined based on the size and structure of the claws on these animals. Take a look at a lobster, for example, it has one larger claw made for smashing and crushing that has pebbly protrusions along the inside of the claw while the other claw is pointier and has serrations along the inside of the claw which makes it ideal for cutting and tearing as well as grabbing. Your crab looks to have fairly thick claws that have serrated edges on the inside as well as points at the end - perfect for grabbing, piercing, and tearing. This makes it likely that it eats inverts and vertebrates in your system as well as whatever else it can find. IME, the crabs that have the little discs at the ends of their claws are more likely to leave fish alone and will concentrate more on picking algae from things (I've had one crab in my system that is a black emerald crab - non hairy variety - for several years now and although it will eat meaty offerings, it doesn't go after fish).