We got crabs

[ccCapt]

I picked up this nice Bali frag/small colony and I noticed a small crab. My camera sucks, so no chance for a pic of the crab, but it's sort of off white color and it looks like the tips of the claws are black, but just the tips, not the entire claw. I always see it moving around in the coral and it doesn't seem to bother it.
So I look in the tank after lights out with a flashlight and I see 2 crabs in the acro. This other 1 is definitely (I think...lol) an acro crab. It is pure white, and it's claws are super thin and flat and also white.
Is the black tipped a bad one? I see it during the day, where the white 1, unless it just blends in so well, I don't see during the day. Can a "good" crab and a "bad" crab live together so close? Should I wait and see?

Here's the coral. Both crabs are in there somewhere.

 

[Innovator]

Probably both a species of acro crab so I would leave them be.

 

[Ziggy953]

Acro crab for sure. I have them in 2 of my acros. Does one of them look like this guy?

 

[ccCapt]

Yeah, thats the pic I found when I was searching. I'm pretty sure that is 1 of them, but I couldn't find any other pics of acro crabs beside that 1 and a purple 1. I always heard black claws=bad, but the 1 I see all the time only has the very tips of the claws black. I guess as long as it's not polyp munching it should be OK. It's way to small to bother any fish or hermit or snail.

 

[Ziggy953]

If it came in the acro I would say it is an acro crab. I had one in my pocillipora that was deep red with black claws. I ended up loosing it in the 120 disaster but it never bothered anything in my tank.

I watched a special on the crown of thorns starfish and those little acro crabs were enough to deter the COT star from eating their home. Pretty cool relationship.

 

[ccCapt]

I saw that too on DiscoveryHD. Either The Planet Earth or Blue Planet...I think.
That was really cool how that crab kept cutting off little pieces of the stars tentacles until it moved off the coral.

If I had a Crown of Thorn star I would be set...lol

 

[Ziggy953]

I have actually seen one at an LFS that I don't visit anymore. It was about as large as a diner plate. It could have been yours for $25

 

[ccCapt]

Over the last couple days I noticed what looked the the purple tips on my tri-colored valadia getting smaller. I just looked at the coral with a flashlight (lights have been off about 2 hrs) and I find the culprit. The valadia is about 4" away from the bali acro with both crabs. You can see the tips of it in the 1st pic. This bad boy made it's way to the valadia and out he came. He is now a resident of my sump.

 

[Ziggy953]

Wow...I'm impressed that you were able to catch him!

 

[ccCapt]

Catching it was too easy. It hung on to the valadia like it was candy. I took the coral out of the tank and it came with it. I grabbed a pair of long tweezers and yanked it off the coral.

 

[Ziggy953]

Oh...well then...nevermind...lol I'm glad you were able to catch it and get it away from one of my personal favorite corals!!