Unknown crab

So I bought a 3 lb piece of lr from a fish store about an hour away. That night I was looking at my tank and saw something move in the rock. Upon closer inspection it was a little red an white striped crab. It's been about 4weeks now he is still alive cause I see it here and there but he never fully comes out of the rocks. Any idea what kind of crab it is and if it's safe? I mean the only thing that has gone missing in the past month is one hermit crab so idk of he killed it or not

 

Probably be a long hunt for that ID.

I would not worry too much unless it is large.

If the crab is still in the small piece of rock, remove the rock and put the rock in the sump or a container until the crabs comes out.

An image if you can get one always helps.

You could also try a trap.

 

agreed...crabs are SO easy to trap....but when I have bought the "bag'o little hermit crabs", I have seen many different colors appear as they grow...black and white, red, blue and black, E blue, orange and black, brown....as coriline stated..could be a task to ID....soooo many. : )

 

It's a normal crab not a hermit and I have been looking all around the web but couldn't find a single picture that looks like him

 

Charybdis hawaiiensis?

Pic below...

 

I think that's it! Looks a lot like it thank you!

 

Well I'm glad I can help. It's a pretty cool looking crab IMO, but you may want to try to get rid of it or banish it to a sump. If you look at the picture, you will notice that it has "pointy" claws. This typically means that it eats meat- aka your fish/ other crabs. A real quick read indicates that they grow to at least 3", which could become very dangerous, very quickly to other inhabitants

 

How do I coax him out of the rock it's full of holes and places for him to hide its rare I see him and I don't have a sump to put him in

 

You may want to look into buying an aquarium trap or making one yourself (pretty easy to do IMO).

You just put some food in there near where he hides and you should get him to crawl out into the trap.

 

yup...I'd get him out...that's a nice hitch hiker...could be a cool trade at the lfs...but I would not want to watch him grow on the back of your habitats. ; )
...just a plastic cup with a string and drain holes...with some bait...he WILL go to it....no question...they stupid ! LOL...and always hungry. 8)