Issues with receding Acanthastrea

[jankyjameson]

I have some Acans that are receding (pic attached), hoping someone could help ID the problem and help steer me towards a treatment plan. Regular feeding seems to slow down the spread of diseased tissue. I had actually already fragged this piece a few months ago because of the same issue, and had a small amount of doubt as to whether I had gotten it all... and apparently I didn't. The other piece that was taken from the same colony still appears to be fine.

Also, if anyone knows of a general "common Acan pests and cures" link, that would be really helpful as well. Here are the tank parameters:

pH:8.0(night)-8.2(day)
KH:9.5
Ca:420
Mg:1400
NO3/PO4: Waiting on a new test kits in the mail, but would be quite surprised if this is the issue. I run an Elos NS500 skimmer on a relatively small bioload, 15%WC/week, carbon 24/7 in a Phosban reactor changed once a month, recently started dosing Biodigest/Bioptim, and have very little nuisance algae even though I feed heavily.

 

[usmc121581]

With the distance of the picture it's hard to tell. Have you tried target feeding it, and moving it out of the light a little? I would try to find a shadow and target feed for a few times a week and see it will recover. It could be stressed, also is one of your fish nipping T it or a hermit crab.

 

[MechEng99]

Any recent changes to the tank? What brand carbon? Any other corals/inverts/fish acting odd? I doubt it's the phosphates/nitrates...acan's are pretty hardy in that respect.

Check a few things for me if you can...I've been seeing some pretty bad stuff with Acan's lately. Is the skeleton turning pink where the tissue is gone? I've been seeing a pink band disease quite a bit on these...no treatment that I'm aware of except excessive fragging.

Also, have you dipped it? I've been seeing a ton of "black bugs" wiping out acan's and chalices in the hobby. If you don't have a dip on hand, I prefer the Bayer insecticide from your local home improvement store. (0.5 ml to 2 cups tank water for 15 minutes.) There are several threads floating around about it...it'll wipe out any pests on that coral.

Keep us posted. Sorry for your luck.

 

[jankyjameson]

Thanks for the replies. @usmc, it has been target fed for the last couple weeks, all polyps accept food readily except the ones that are melting. I also noticed bubble algae seemed to be growing out of the mouth of the "infected" polyps, which I've actually noticed in the past alongside similar acan issues. Already have it out of direct light, and have been observing night time as well; but haven't observed any pesky critters with the munchies.

@MechEng99, Seachem Matrix carbon, and yes actually there have been a few recent changes to the tank; I added dosing pumps and sloooowwly brought Ca and Alk from where they where to appropriate levels, and I started dosing Prodibio Bioclean; though the problem seemed to be starting before any of this. I'm sure the changes in water parameters didn't help it too much either, though. I did not notice a pink band where the polyps were receding, though I did notice something like this on a badass Micromussa(?) colony I lost about a year ago. I've dipped it in TM Pro Coral Cure and Lugol's, and haven't seen any pest fall off.

I went ahead and fragged it yesterday, I have my friends Inland Reefkeeper saw over here so I decided to just take advantage I applied superglue right along the edge of the cut flesh in an attempt to ward off any more infection. All polyps are fluffy and looking fine this morning! Will post some more pics when/if it recovers a bit more and starts to encrust.

 

[MechEng99]

*IF* it keeps extending tentacles, looking fine, etc while it's still receding, I would try the Bayer approach above. I haven't had luck treating the black bugs with CoralRx or Lugol's.

As long as your test kits are right and you didn't overcorrect, dosing shouldn't be a problem...neither should the BioClean (I use it).

 

[Dimorb]

How did it go?

I have alot of acans.. all have been doing well so fare but for about a month ago 9 colonies have been starting to die/loose tissue.

I have alot of other lps corals in the same tank and they show now signs at all.. only acans affected..

What did you do? How did it turn out?

 

[ssteal]

Just wondering what salt u use

 

[Dimorb]

Me?

I use tropic marine reef salt.

 

[jankyjameson]

@Dimorb, the only thing I've had success with so far is fragging the colonies that are losing tissue. Nothing else seems to stop it, in my experience, or at least it hasn't yet. Using the Inland saw it was relatively easy to cut right between the polyps, so any unintentional tissue loss is kept to a minimum. You have to be sure to cut into the UNinfected region, across the entire cut. Every colony that I KNEW I had 'gotten it all', I was right, and they all began growing new polyps again within a month. Any colony where I had any slight question (cutting close to the line of tissue recession, rather than playing it safe and sacrificing an extra polyp or 2); those all started receding again.

 

[Jstn]

I had the same problem, turned out to be a worm eating/ irritating my acans. I found the bayer dip would help them for a few days, then they would resume declining.