Nudibranches eating my zoas

[jck16]

Has anyone had this problem? In the last couple of weeks, I've found 2 nudibranches around my zoas, which seem to be the type that eats zoas. I've definitely noticed one or two colonies seeming to decrease in number, and I'm worried I might have an infestation?

Do they usually come in bunches? I killed 2 already (the first one I threw into the fuge, where I think it starved).
Also, what should I do to take care of zoas that have been damaged by them?

If anyone has any input on this, I'd really appreciate it.

 

[premilove]

man take them out now!!!!! as far as saving i really do not know what you can do. PLEAAAAAAAAAAASe take those nudis out! they will finish off your zoas head by head.

 

[kigs]

try a magnesium dip. not effective for eggs, so set it apart for 2 ~ 3 weeks.

 

[KathyC]

try a magnesium dip. not effective for eggs, so set it apart for 2 ~ 3 weeks.

Magnesium dip? Never heard of one, can you tell us about this concept?
I know you're into zoas, is this something new?

Jck (it is Jack?)...you do want to take a look for the nudi you threw into your fuge as it might still be alive or could have possibly laid eggs in there.
Basically you need to dip each of your zoa frags in (this is the standard action for zoa eating nudis..) Lugols solution (read the instructions on the bottle and follow the directions). If that gets rid of the adult nudi's, you will still need to get rid of the eggs. The only way to do so is by scraping them off, so you will need to inspect each zoa carefully.

 

[jck16]

I think I see the one in the fuge, and it def seems to be dead.

How often do they lay eggs? I thought I saw something that looked like eggs on one of my zoas They're already gone though...so maybe I'm looking at a major infestation.

I'll try the Lugol's solution, but I first want to monitor the situation for about a week to see if there are any more I can manually remove.

 

[Marteen]

Alright here is what you need to do.

First, you need to remove the nudis that are already in the tank. This is actually pretty easy since they spend almost their entire lives on the zoa colony they are killing. You can remove the nudis by dipping the corals in a 1 gal FW bath with 4 drops of Lugol's iodine.

When you are dipping you have to remember that the corals may already be pretty stressed so adjust your dip times accordingly. For a relatively healthy colony I would suggest a 3 minute dip. Once you have dipped the colony pick it up and swish it vigorously in the water and watch those little nudis fall off.

However, nudi eggs will not come off in a dip and need to be removed by hand. What works for me is to place a paper towel over my fingers and then hand pick them off. The eggs are slippery and resist things like tweezers, but will stick to a paper towel.

If your colony is in really bad shape try the same dip but use saltwater to limit the stress caused to the zoas.

I believe the eggs incubation period is around 14 days so once you have eliminated the adults you will need to do a second set of dips in 2 weeks to get the next batch. Just keep repeating this process until you've got them all. You can also try this dip to prevent future outbreaks by dipping incoming corals as well. Hope this helps.

 

[jck16]

So after some observation, it seems like the slugs are gone for now but there are these pale spots now on the zoas that I suspect are "zoa pox"...unless slug damage looks like pale dots.

I tried a hydrogen peroxide bath today because I didn't have time to go to the pet store to get Furan-2 (a suggested cure), so I'm seeing if that'll help at all. Yesterday, I used some tweezers to scrape off a few of the spots that could come off. In any case, it's all rather worrisome, since my zoas used to be open all the time.

Is there something else I should be doing?

 

[KathyC]

Did you remove & dip ALL of your zoas? How many adults did you find?

Posting a pic of the suspected zoa pox would be helpful.

 

[jck16]

Here are some examples of the spots I happened to notice from a picture I took about a week ago:

These spots have since progressed to other zoa frags too. They look like little pustules, and the scrapings I took yesterday looked like yellowish pus.

 

[rookie07]

I think that is the eggs...is it a lot of tiny circles, all forming a small swirl?

 

[Bob 1000]

What color is this nudi I found a all orange one in my tank 2 month's ago.. It's only a 1/4 of an inch and looks like a sponge with 2 eyes and a nudi butt..

 

[KathyC]

nudi eggs

What color is this nudi I found a all orange one in my tank 2 month's ago..

Tobin..nudis assume the color of whatever zoanthid they were last eating which is why it is so hard to see them on the zoas..here is an example from Zoaid..


dead center...

 

[KathyC]

So after some observation, it seems like the slugs are gone for now but there are these pale spots now on the zoas that I suspect are "zoa pox"...unless slug damage looks like pale dots.

I tried a hydrogen peroxide bath today because I didn't have time to go to the pet store to get Furan-2 (a suggested cure), so I'm seeing if that'll help at all. Yesterday, I used some tweezers to scrape off a few of the spots that could come off. In any case, it's all rather worrisome, since my zoas used to be open all the time.

Is there something else I should be doing?

Who suggested Furan2?? What what it supposed to get rid of...the eggs? Nothing gets rid of the eggs except for scraping them off manually
Where did you come up with the idea of hydrogen peroxide?
Have the zoas you dipped in that reopened?

 

[jck16]

I definitely had those eggs laid on one of my zoas about a week ago...but I have no idea what happened to it because it's gone now. I'm assuming they hatched. I remember tryin to pick at them when they were there, thinking they were something else, but gave up when they didn't come off easily (stupid of me).

Btw, I have dipped MOST of the zoas in RO water to check for nudis...at least the ones on frag disks. Esp the one I first noticed the nudi on w/ eggs and the ones that stay closed. Nothing came up. The others I'll get to this weekend, since they seem to be doing fine. I feel like these spots though are a whole new can of worms. They're NOT like the eggs at all; they look like little white blisters filled with pus, which sounds like zoa pox from what I've read online. Or from my putting them near metal halides, according to wetwebmedia.com

Furan-2: http://www.zoaid.com/articles004.php
Peroxide: http://www.reefhobbyistmagazine.com/downloads/pdf/version1.pdf

Zoanthids, like any other marine animal, may harbor pests or be subject
to disease. The reef aquarium hobbyist should inspect newly acquired
zoanthid specimens for such things as predatory nudibranchs,
zoanthid spiders, sundial snails, foramaniferans, asterinas, red
planaria, fungus, and white “zoa pox”. These may be remedied by
a variety of treatments including manual removal, fresh or salt water
based dips of iodine, hydrogen peroxide, fluke/flatworm medications,
or Furan-2, depending on the predator or ailment.

I have yet to see them in daylight, but the ones I actually dunked in a diluted peroxide mix (as opposed to topical treatment) are already open w/o the lights.

 

[KathyC]

If the spots you saw a week ago were nudi eggs and they are gone now, then yes, they probably hatched which means you may have a bunch of tiny nudis munching away.
You really need to dip all of your zoas no matter how much of a pita that is or you soon won't have any zoas. Please keep in mind they only eat zoas...
It is more likely that the spots are zoa eggs and not zoa pox as you have already seen an adult nudi. You said you did not have any fall off when you did the dip (Lugols is the suggested solution as it is the most effective), so that means they are still in your tank.
They do not move slowly btw...and could be on a different colony/frag/zoa each hour. Late night you may also find some on your glass, but 99% of the time you will find them in a zoa..munching away.

 

[Bob 1000]

Thanks Kathy.. I think this is a good one I don't have any Zoas..

 

[jck16]

See, but this is the thing that's most bothering to me. I feel like I have an imminent wave of little nudis munching away, but I am absolutely positive that these white spots are not nudi eggs though. As I have said, I have seen what the eggs look like, and these are definitely not it. What I would like confirmation though is if they could be signs of nudi damage or if, as I suspect, they're signs of "zoa pox", which is a whole different issue I'd have to deal with.

In either case, I will continue to do dips (of all zoas this time) and monitor what happens. And I really do appreciate the input everyone has.

 

[Marteen]

Since zoapox can appear for a number of different reason, stress being one of them. The appearance of the nudi's could be the cause of the zoapox as well. I would suggest dipping the zoas for the nudi's in Lugol's Iodine as well as dipping them the next day in Furan-2. As far as I know Furan-2 is the only cure for zoapox that has been known to be effective.

Now is the best time to dip for nudi's for you. Since they are small they will not have had time to become mature and lay eggs. This gives you a small window of opportunity to kill them off before they can reproduce. Good luck.

 

[jck16]

^^^ Ended up following Marteen's advice after researching some more on the Internet and consulting with Eddie @ WWOF.

Dipped all zoas several times in both iodine and Furan-2 with nothing coming up.

Bad news: I lost all 6 of my radioactive greens, 2 Tubs Blues, and about 60% of my Whammin Watermelons.

Good news: Remaining zoas are doing fine and about 98% have reopened. Most traces of zoapox are gone (or the zoas that were affected are gone :irked.