This crab eating my coral?

snail · 11-28-2007, 08:51 PM

I found these guys on a piece of coral and need to ID them good or bad. I don't like the way they act. I haven't had any coral, this is my first piece, it came attatched to a piece of liverock that was attatched to the urchin I wanted.

So I decided not to break up the set, I liked the colors on the rock too. But when I got home with it, I saw this hanging on the coral. I removed him from the coral, I then thought what damage could he do being so small, and after researching since tuesday have not solid info.

As he was re-introduced, he stayed on the rocks. Then I saw him back on the coral, but then I noticed it wasn't this guy but another one.

When I removed the second one the coral looke pretty bad where he was encased.

Now the coral is all hiding away and not happy. This is not a large peice of colt coral so I hope it will recover.

I need a positive ID somehow on these guys. One person mentioned he looked a bit like a gulf weed crab. His shape is like an acro crab, but no distinguishing black mask.

He swims when pestered, like a crawdad it remined me, but sideways and pretty fast. When caught by hand, seem just fine hanging onto my fingers.

Please help me, I don't want to kill anything, and need to know if I can keep these little guys or not.

Thanks
Dave

dobejazz · 11-28-2007, 09:16 PM

Welcome to TRT !

I'm not sure on the crab ID - From what I've read the hairy ones are bad.

snail · 11-28-2007, 09:25 PM

Hi dobejazz, I found this place looking for any info on these. Still looking. Is there a site that is expert in crabs?

If I had a ready supply of coral, I would chance it. I mean it is kindof cute when it is not feeding. It is just so darn small I cannot see what it is doing, good or bad, to me, looks bad. Without the crabs in the coral, they don't seem happy, but that may be from me messin with them also.

bwillcutt · 11-28-2007, 09:44 PM

Worlds smallest snow crabs cool!

Debs · 11-28-2007, 09:53 PM

Boil it and eat in on a cracker

schmidt01 · 11-28-2007, 09:57 PM

It looks like the crab is defending the coral in that picture, which is kind of cute! I'm not sure if that's actually what's happening, but it's a neat picture. I've read about crabs online that host in corals, so maybe he's not a bad guy. I'm not sure though.
I did a search on google for white crabs, but the only thing I found was one that lives primarily in the sand so I don't think that's your guy. I'll keep looking though. I thought I had a crab in my tank a couple of weeks ago and I found a lot of crab ID sites online, but I don't remember seeing any white crabs. It's driving me nuts right now because I can't find any of the websites I looked at now. If I find them again, I'll post them for you.

snail · 11-28-2007, 10:11 PM

Thanks Schmidt

I am at witts end. Been joining lots of forums and talk places, no positive ID yet.

I didn't like what I saw so I pulled them off. Just now, the coral was coming back out. In the pics and others I have and from viewing this crab, I cannot tell if the coral is hugging it or trying to expell it.

The coral may think it is friendly, but then when the crab goes to eating, it doesn't know what to do with it.

The crab did not seem to use the big pincsher for tearing or binching, but to gather or bring the coral to its mouth.

I appreciate you help, I wonder if I have a newer species of crab that is worth millions of dollars

Then I will feed them coral all day long

snail · 11-28-2007, 10:15 PM

Quote:

Originally Posted by bwillcutt

Worlds smallest snow crabs cool!

Believe it or not, the closeset thing in shape and looks color etc was on a beach and looked to be about a foot wide. I seriously think this could grow that big, but I know nothing about where crabs come from.

schmidt01 · 11-28-2007, 10:17 PM

Check out this site... this might be your crab:
http://www.edge-of-reef.com/brachiur...antidae4en.htm

It looks similar to me. Not sure if its reef safe though... still researching that...

schmidt01 · 11-28-2007, 10:24 PM

I'm keeping my fingers crossed for you that its a new species and you'll make millions of dollars!

If it is a sponge crab, it might be trying to tear off a peice of your coral to attach to its back for camoflauge (sp?). Apparently if they lose their sponge they'll go through great lengths to get them back and they will use bits of coral if they can't find a sponge. Try googling sponge crabs and you'll find some more information. I think its a good thing you pulled it out of your tank. Even if its not a sponge crab, its usually not a good crab if it has pointy pinchers.

snail · 11-28-2007, 11:27 PM

Quote:

Originally Posted by schmidt01

I'm keeping my fingers crossed for you that its a new species and you'll make millions of dollars!

If it is a sponge crab, it might be trying to tear off a peice of your coral to attach to its back for camoflauge (sp?). Apparently if they lose their sponge they'll go through great lengths to get them back and they will use bits of coral if they can't find a sponge. Try googling sponge crabs and you'll find some more information. I think its a good thing you pulled it out of your tank. Even if its not a sponge crab, its usually not a good crab if it has pointy pinchers.

Hey thanks, I have them isolated in a container in the tank with a small piece of rock. I sure would like to get this figured out.

I just started to set up a refugium or maybe quaranteen tank, but no heater yet. Just added a sand bed and some shells, no live nothing. Water has been circulating for a day now.

These guys seem to be rare, maybe I should ebay them

seasalt dreams · 11-29-2007, 12:09 AM

If the crabs are happy in the coral, and the coral looks good, its probably some sort of symbiotic relationship, like my acro crab is on my birdsnest. He has been in that coral cleaning and protecting it since I got it. If I remove him, he will die.

Geoff · 11-29-2007, 11:48 AM

i am not real keen on crabs. i really do not like crabs that have pointy pinchers.

G~

snail · 11-29-2007, 12:19 PM

Quote:

Originally Posted by seasalt dreams

If the crabs are happy in the coral, and the coral looks good, its probably some sort of symbiotic relationship, like my acro crab is on my birdsnest. He has been in that coral cleaning and protecting it since I got it. If I remove him, he will die.

These look very similar to the acro crab, just missing the black stripe. They act much like the acro, but more aggressive toward the coral. I think if the coral was bigger and supplying more food, these crabs wouldn't be eating the coral itself or at least what I believe to be parts of coral that the coral needs.

I will keep them separated and watch. What else might these crabs eat so I can keep them healthy?