Crab ID Help

[Blue00]

I found this sucker biting my new caulastrea, almost reducing it to the bone. It only comes out at night, I just managed to catch it and for now I put it in the sump. Can you identify it and let me know what it is? Also, can it survive in the sump? (I don't have a refugium, so I don't think there's much to eat.) Or should I kill it quickly? I don't want it to starve to death.

 

[TX_REEF]

double post glitch

 

[TX_REEF]

it looks somewhat like a calico crab: https://tbsaltwater.com/blogs/reef-not-safe/calico-box-crab-hepatus-epheliticus

If you don't want to keep it in fuge, I'd give it to LFS rather than kill it, pretty rare there are folks who might like it.

 

[BristleWormHater]

it looks somewhat like a calico crab: https://tbsaltwater.com/blogs/reef-not-safe/calico-box-crab-hepatus-epheliticus

If you don't want to keep it in fuge, I'd give it to LFS rather than kill it, pretty rare there are folks who might like it.

Dont think the two are very similar, the shape of the carapace is very different.
This strikes me as some species of stone crab, family Menippidae, although it may be Xanthidae as well. The two families have pretty similar morphology (Menippidae was once considered Xanthidae) Would need better pics of the claws and the mouth from @Blue00.
Definitely not reef safe though, agree with taking it to the lfs or putting it in the sump.