Sup Fellow Stick Keepers,
I'd like to share my experience with the notorious pest Aeolid
nudibranch that preys on Montipora species, and how I (successfully) treated a M. Confusa. I saw that Rob had already posted a nice article about Red Bugs, so I think it's a good idea to post something about the
nudibranchs.
IMO, the
nudibranch is more voracious and more difficult to eradicate than any other SPS pest, as it requires both manual removal and a series of chemical dips.
A little background...
Based on my experience and reading a few articles, these aeolids seem to reproduce
asexually-- meaning one
nudibranch can lay hundreds of eggs and does not need a female to do so. In my experience, they seem to like M. Confusa and M. Capricornis the best, but in no way are limited to those species of Montipora. These pests are very voracious as I've seen 3 adult
nudibranchs consume a 3" Confusa in one day.
Monti eating
nudis are very easy to spot.. but the eggs is a different story. You will have to stare at the coral closely (and maybe use a magnifying glass) to see the egg clusters. By the way, a regular
nudibranch lays eggs in a spiral fashion - which is easy to see. Monti eating
nudis lay eggs in a cluster formation. To make matters worse, their eggs are semi transparent!
Recently, I made a trip to some of my
LFS and sure enough, I saw some infected pieces. I spoke to the owner and was shocked to hear that most of them don't even know that these pests do exist - one guy thought that the reason his corals are losing flesh was because of their new lighting! One
LFS even offered me free (infected) colonies for me to take home and try my luck at curing them. All specimens that I treated have fully recovered by the way.
Here's a M. Confusa that was heavily infested when I acquired it
Treatment
There are many treatments for this pest including Lugols dip,
FW dip (not recommended), and Levamisole, but most of these can only eliminate the
nudibranchs but not the actual eggs. Here's what I did::
1. Break the infested part and throw it away. No matter how clean the coral looks, the eggs are usually hidden in deep crevices so you can't take a chance here. ONLY KEEP the top part of the coral and throw away the rest.
2. After you cut the coral, again you will have to visually inspect it carefully for eggs. Remember you are looking for CLUSTERS of eggs. If you see them, you need to scrape these with a soft toothbrush and clean it with tankwater.
3. After the coral has been cleaned, prepare two containers - one with three cups of tankwater + 20 drops of Lugols and the other with just tank water. You will now dip the coral for about 10 mins while still inspecting for eggs
4. If you see more eggs, scrape it again with your toothbrush. When you are done, dip the coral one last time. This time into the clean tankwater.. this is to finally rinse it off.
5. You're done. Here's the actual piece that I treated-- This Confusa has grown way bigger than what's on this pic.
Summary
If you find a
nudibranch in your tank, you will have to do this procedure for EVERY Montipora that you have. An ideal solution is to transfer the "treated" colonies to a treatment tank and observe them for a week or two. If no
nudis show up then you can put them back in the display. This procedure should also be used when acquiring NEW specimens - regardless of whether or not the
nudis are visible. Look for areas that are white and no flesh - this is a dead giveaway that a
nudi is present.
Some people have reported good results by keeping wrasses in their display tanks. While this is a good "natural" population control method, it is just a temporary band-aid solution and the original problem usually comes back after a while.
As always. a quarantine procedure on NEW specimens is
highly recommended.
Please post any questions that you may have, and I'll try to answer them.
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