Crab ID?

[eschaton]

Hey guys,

I have TBS rock, which has come with a lot of crabs. Discounting the hermits, for the most part these fall into three groups:

1. Gorilla crabs. Still have far too many of these. They're really obvious both in terms of their looks and behavior (secretive, predatory, etc).
2. Decorator crabs.
3. Small, reddish crabs which just pick at the rocks.

Then there's this dude:

I don't know what to think of him. Unlike the gorilla crabs, he is not shy, staying right out in the open. He picks at the rocks and seems harmless. His claws are fairly small, but he is a very large crab. He almost looks like a large decorator crab, but he's really not that "decorated" aside from a little algae which may be incidentally growing on him.

Thoughts?

 

[Mike N]

Looks like a decorator crab to me as well. Nothing to worry about if so

 

[45ZoaGarden]

Looks like an emerald crab covered in detritus imo

 

[eschaton]

While I'm at it, any idea on this crab?

 

[45ZoaGarden]

While I'm at it, any idea on this crab?

Can you get a pic of it’s claws?

 

[KJ]

While I'm at it, any idea on this crab?

Mithrax crab.

 

[eschaton]

Can you get a pic of it’s claws?

Better shot of the crab. Maybe not the exact crab - I have at least three in the tank:

In other news, I consigned the crab at the top to the sump tonight. I don't know what was going on, but he started attacking my red tuxedo urchin. I think he was just trying to grab **** the urchin was carrying to plaster on himself, but I wasn't going to take a risk - particularly because someone was apparently munching on the leather coral seen in the first picture and he seems a likely suspect.

 

[45ZoaGarden]

Mithrax crab.

+1 or in other words, a red emerald crab.

 

[45ZoaGarden]

Better shot of the crab. Maybe not the exact crab - I have at least three in the tank:

In other news, I consigned the crab at the top to the sump tonight. I don't know what was going on, but he started attacking my red tuxedo urchin. I think he was just trying to grab **** the urchin was carrying to plaster on himself, but I wasn't going to take a risk - particularly because someone was apparently munching on the leather coral seen in the first picture and he seems a likely suspect.

He was probably trying to get any algae the urchin was carrying.