Acro crabs -- Who chooses to use / keep them with their SPS?

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#1
Since doing some reading awhile back I've been interested in Acro crabs. Apparently they can form a pretty solid mutualistic relationship. I've unfortunately lost the link but there was an extensive study discussing how Acro crabs help to keep the coral healthy and growing optimally -- Not only by cleaning detritus which settles on the coral itself, but defending against predators and vermetid snails.

The efficacy of the crab in an aquarium setting remain to be studied, but several of the prominent SPS guru's at RC and other places keep and enjoy having these acro crabs.
 
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#2
I would love to have some in my next reef. I love the acro crab pics, and it's another cool symbiotic relationship to observe.
 

Six2seven

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#3
The way i see it, if someone has an acro crab in their system then it tells me they are not dipping correctly if at all.
 
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#4
^^^ What he said lol But on a real note they are super hard to get into your system intentionally. I have just recently been able to acquire one that has made it. They are extremely fragile
 
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#5
I would love to have them. In all my years of reefing I've only seen one in my tank and it only lasted about a week before it disappeared.
 
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#6
@Six2seven & [MENTION=8656]M3ace9[/MENTION] -- Most people who keep them remove them from the corals before dipping. This is assuming they're getting maricultured / wild corals, and intentionally digging through them.

You might also get them from an LFS that gets wild corals if they're willing to give them a look before dipping. I think this kind of relationship might just be the forefront of reefing. THey not only defend their host (the corals), but they'll work to take out anything that may impede coral growth (vermetid snails) and they've been shown to improve coral growth by keeping them clean of debris, mucous, and whatever else winds up on your Acros.
 

watchguy123

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#7
I think acro crabs are fascinating and as has been stated not all that well understood. Talk about a "natural predator" of potential pests, they might and I mean might play a significant role in acro protection. I've never had one in my tank though
 
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You're right @watchguy123, anything that attacks the coral is an attack on them. They may not be able to take out an army of red bugs, but they could make quick work of those first few before they start laying eggs everywhere...

One of the other potential problems is most people struggle to get colonies sizable enough to make Acro crabs happy! They need something densely packed about the size of a baseball before they feel comfy in their home and don't all fight over the biggest colony in the tank. They also for who knows what reason prefer some acros to others, possibly due to camouflage or the crabs perceived better/worse placement of an Acro.. As in, you put the crab on the acro in the corner with crappy flow and low light and he'll be looking for a better apartment ASAP. A few people have taken them off acros 3-4 times to place them where they want them, and the crabs migrate every time.

Pretty cool little relationship they form
 

deaclauderdale

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#9
I think acro crabs are fascinating and as has been stated not all that well understood. Talk about a "natural predator" of potential pests, they might and I mean might play a significant role in acro protection. I've never had one in my tank though
In the wild they've been known for taking on 'Crown of Thorns' stars that attack the acro they're living. This definitely supports your point of their playing a significant role in acro protection.

Reef keeping is life!
 

drexel

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#10
I have one on my A. humilis. It's the only acro that I didn't dip, but I did take precautions. I knew the source of the acro and I wanted the crab to survive. I removed as much of the bottom material that was attached to the (mini) colony, then super glued the entire bottom and sides leading up to the "flesh". It's not something that I would recommend, but I knew the risks and wanted to keep the crab alive. Again, not something people should copy, that's my PSA.
 

Smite

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I was putting in an order in DD and saw they had some acro crabs avaliable. I ordered one but haven't had much time to observe it. Surprised me they shipped it in a small multi branch birdsnest frag. I removed the crab and dipped the browned out birdsnest. I placed him in one of my larger "colonies" but haven't seen him since. I'll try and find him/take a picture when I get home this weekend
 

JOSE CASAS

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#12
The way i see it, if someone has an acro crab in their system then it tells me they are not dipping correctly if at all.
Not true, I know several reefers that take the crab out of the coral an then dip. I have also seen AC for sale with out the acro.
 
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#13
Very cool [MENTION=844]JOSE CASAS[/MENTION] & [MENTION=7067]Smite[/MENTION], I think they're awesome little critters and I will try and get a couple for my new system when some Acro's start growing in.
 
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#14
I got from a colony like2-3 years ago, that colony died and it moved onto another colony, i think its still alive ill snap a pic later on.
 

lowbudget

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#15
back in the old days when i had a mature tank i had a few AC in my tank. really cool critters. they clean off the coral what my pumps can't get to.
 

innerspark

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I was putting in an order in DD and saw they had some acro crabs avaliable. I ordered one but haven't had much time to observe it. Surprised me they shipped it in a small multi branch birdsnest frag. I removed the crab and dipped the browned out birdsnest. I placed him in one of my larger "colonies" but haven't seen him since. I'll try and find him/take a picture when I get home this weekend
Where did you order from?
 

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