Acropora eating crab...

[patrickross]

Has anyone ever seen a crab eating acropora? It came in on a piece of stylophora I bought some time ago, didn't seem to bother it really but, it has now moved into an acropora colony and I think it is actually eating its polyps. It isn't the small white type, this is a little bit bigger, dark-green/brown, and hairy/fuzzy.

 

I don't have a camera right now.

 

 

I don't have the heart to kill this thing but have nowhere to put it right now.

 

Thanks in advance.

[Oregon]

Has anyone ever seen a crab eating acropora? It came in on a piece of stylophora I bought some time ago, didn't seem to bother it really but, it has now moved into an acropora colony and I think it is actually eating its polyps. It isn't the small white type, this is a little bit bigger, dark-green/brown, and hairy/fuzzy.

 

I don't have a camera right now.

I don't have the heart to kill this thing but have nowhere to put it right now.

 

Thanks in advance.

 

It could be anything from a brown colored mithrax(some will eat coral but probably isn't this), a red or blue eyed reef crab, xenia crab or any number of other hairy pest crabs. No point in identifying it really. This article excerpt will tell you anything you need to know about hairy pest crabs.

 

I wouldn't kill it, just catch it and put it in your sump or fuge.

Drsfostersmith.com sells a decent pest trap for a reasonable price too.

 

 

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Pests in the Reef Tank, Part 2

by Mike Paletta

 

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Unlike the Xenia crabs which are specialized feeders and easily removed, the Hairy crabs are generalized feeders and are very difficult to remove. These crabs will eat and destroy anything that they can get a hold of including leather corals, hard corals, mollusks, tube worms, and anemones. These crabs only come out at night and are very difficult to remove. These crabs can also get very large and are therefore potentially extremely dangerous in terms of the havoc they can wreak on the inhabitants of reef aquarium. In this crab group there is a specific group of crabs that feed on the polyps of SPS corals. These crabs are easy to spot as they have very bright blue eyes. These crabs usually come in pairs so it is necessary to remove both of the animals in order to limit their destruction of coral heads. The best way to limit the destructiveness of these crabs, as previously noted, is to prevent these crabs from entering in the first place. Since this is not always practical, there are at least two other methods for their removal. The first method may seem rather cruel, but it is necessary. A piece of bait, i.e. shrimp or squid, is placed near the crab's known residence. This is best done right before the lights go out. A red lamp is then placed near the tank so that the bait can be viewed. If you are fortunate, soon after the lights go out the crab will approach the bait. At this time the crab can be smashed with a piece of PVC pipe and removed from the tank. This method requires patience as it may take more than one night, and also quick reflexes as the crab moves surprisingly fast. The second method I have tried is to use a wide mouthed glass jar as a trap. I place the jar on at a slight angle near the crab's home and place the bait in the bottom of the jar. Once again I do this right before the lights go out. If I am lucky, the crab will smell the bait and enter the jar. However, due to the smooth sides and angle of the bottle, once the crab enters the jar he will be unable to crawl back out and he can be removed in the morning. The only problem with this method is that it will usually only work when the crab is hungry enough to overcome his fear and enter the bottle. Otherwise what usually is caught in the jar are fish and the tank's desired shrimp inhabitants.

[patrickross]

Thank you, Oregon...it DOES have bright blue eyes, is hairy, was eating my acropora spp. I removed it, is in a glad container with holes punched through it. I don't know what to do with it. I don't have the heart to kill it. Either way, glad it is out of my sps.

[c est ma]

If you don't have a sump, try taking it back to your lfs. Maybe someone with a FOWLR will want it.

 

--Diane

[patrickross]

I work at my local fish store. Ha. Anyway, the stylophora it came in on I bought at another lfs, they seemed to think it was a commensal acropora crab. I always had suspicion but I really neglected everything for a short while after moving the tank twice. I was so overwhelmed. I think it'll most likely die without eating it's proper diet anyway.