crab id?

[Coroner47]

I've had this crab in my tank now for about 4 months. He came in on my live rock & he seems totally harmless. Can anyone identify him? thanx

 

[VacavilleFC3S]

thats definitely a rock crab, there evil and will kill your fish while they are sleeping, i suggest tossing it out.

 

[kalapnath]

it looks like a emerald crab

 

[VacavilleFC3S]

without a doubt it's a rock crab, look at the claws and how they have black tips, also the body shape

 

[Coroner47]

I don't have any fish in the tank & don't plan on having any, just crabs & shrimp. Should my other crabs be ok with the rock crab? He hasn't bothered any of them yet. Ive seen him eating molted crab & shrimp exo-skeletons, but never anything live.

 

[VacavilleFC3S]

he'll probably eat anything he can get his hands on, i'd toss him and replace it with an emerald crab or porcelein

 

[MRinvert]

Where is Your live rock from?

The rock Crab from The Southwest pacific is known to be one of the nastiest creatures alive.

The Rock crab of California is also bad, but not quite as nasty.

I suggest you toss it either way, can really harm your livestock.

 

[geemanaz]

it look like a Xanthidae Crab

 

[BEASTIEPENDENT]

Hi there

This indeed is a Xanthid crab. The black claw tips indicate that too. But that does not say anything about "friend or foe".

Coroner: You should look if You can see its claw have spoon-shaped tips or sharp ones. In the first case You have a Xanthid that mainly feeds on algae and detritus. In the latter case it would be a predator. Anyway each crab is an omnivore opprtunist, e.g. even algae feeders take every proteins they can get.

Your tank does not look like even a predator crab could make heavy damage. The hermits can retreat into their snail shells, shrimp should (!) be to fast swimmers, what else should there be the crab could eat?