suns and dendros suddenly dying

[euromomtx]

Just three weeks ago my suns and dendros looked like this:

Now it looks like this:

Some of the colonies I had for almost a year. Some are fairly new. The common thing I can see is little yellow dots on the sick corals.
Are the yellow dots a symptom of decline? Or the cause of decline? (in other words are the yellow dots just bits of dying tissue or are they parasites or pahtogens and I need to remove the affected ones immediately to save the rest?)

A few things have been going on within those last 3 weeks:
I was having trouble keeping up with caulerpa racemosa and rather than Keep fighting it back I decided to take out the 3 large rocks that it was on.
This started a major diatom outbreak.
I hooked up a new phosban reactor with GFO to help because I figured I probably lost quite a bit of good bacteria by removing the large rocks.
I also started biopellets just a few days ago.
I usually never use hand lotion but have been using lotion a few times (not sure how well it washes off) but especially during the large rock rearranging some lotion could have entered the water.
The corals haven't been as perky for a week or so but noticeable decline occured during the last few days.

I've been doing daily 5% water changes for the last few days just in case.

So what are the yellow dots on the dying corals? What should I do?

 

[achillesmf]

The yellow dots are nudibranchs. Start the treatment ASAP.

 

[slapshot]

Yep, I agree start treating!

 

[euromomtx]

Okay I did treat and look what happened:

It expelled lots more of the yellow worm things. I still don't know if it's part of the corals or a pest/nudi

 

[GoingPostal]

Those look like mesi-whatever filaments to me, are they actually falling off the coral or part of it? My dendro has shown them occansionally when extremely stressed or after damage. If it were me I would take the GFO offline and do massive water changes. Have you tested the tank? Results?

 

[euromomtx]

everything looked fine on the results. only alk was high at 13 dkh
calc 420, mag 1300, no detectable nitrate, phosphate or nitrite, ph 8.0 in the am and 8.3 before lights out

 

[Western_reefer]

Okay I did treat and look what happened:

It expelled lots more of the yellow worm things. I still don't know if it's part of the corals or a pest/nudi

I have the same orange stringy stuff, no where near as much in the picture tho. Is it a pest or is it guts or something?

 

[TheH]

There is supposedly some kind of flatworm or nudibranch that affects sun corals that looks just like their extended polyps. I can't seem to find the article right now though.

 

[achillesmf]

Hi, kill these bastards! Physically remove all you can and dipping dipping everyday! I would remove the suns to treat on separate tank, it will kill the nudis from the main system of starvation. When the nps are better you can return.:hmm4:

I'm so sorry. Nudis have devastated my zoas in the past It will be a war, if you have discipline you'll win.:beachbum:

 

[uhuru]

Okay I did treat and look what happened:

It expelled lots more of the yellow worm things. I still don't know if it's part of the corals or a pest/nudi

I would cut off some of these yellow filaments and look at them under a microscope before continuing treatment. It could be a stress reaction.

 

[euromomtx]

uhuru I think it is a stress reaction - part of the corals' guts so to speak. I put in a poly filter and some carbon yesterday and they are looking a little better this morning.
I am seriously thinking I must have gotten lotion that I had on my hands into the tank and hopefully the poly filter and carbon along with water changes will get the stuff back out.

 

[dpdp225]

That looked like it was planula to me. My corals do the same thing all the time. The planula will either settle on the coral or get carried away to another part of the tank and then becomes baby sun corals. I've had my adult sun corals three years and some are just starting to die off, but I have two rocks of all new babies that range from a month old to 3 years old. But the best thing right now I would think is just let them rest from whatever you treated them with and don't do anything else drastic. They should recover if the treatment says it's okay for sun corals. If you feed other animals and they extend their polyps to feet they be fine. I moved mine out of water one day from one tank to the next and they kind of looked like yours did after the treatment. I freaked out and thought I totally toasted them... but they ended up being fine. They just looked like they were dying.

 

[euromomtx]

Thanks so much Debbie. That makes me feel a little better. The lights went out and I do see most of them opening up in anticipation of dinner.

 

[stunreefer]

It could be a stress reaction.

+1, not a pest, they're stressed out... bad.

 

[rowjimmy]

+1, not a pest, they're stressed out... bad.

+2

I once had a parasitic crab eat the center out of a Tubastrea polyp. He liked to hang out in the center of the "cored out" polyp that he ate. The remaing flesh of the polyp and the surrounding polyps all put out those "yellow strings" from the stress of the injury.

Once I caught and removed the crab, the "yellow strings" dissapeared, and the polyp healed and eventually regrew. The colony is now fine and healthy.

 

[euromomtx]

Hi, just wanted to say the stringy picture was taken right after the pest treatment. They didn't look like this for long. I found a coral with multiple babies in those areas the yellow specks were and several yellow specks.
I am convinced the guess about planula was correct.
I am sure it's still stress related kind of like when carnation corals drop a lot of babies in the tank when they're dying.
But at least it's not a parasite and the corals are looking better plus a lot of tiny baby corals.

 

[dpdp225]

I'm glad you didn't lose the babies. You may see some in other areas of the tank if some of the planula was carried off by the current. Just for future reference, it might be better to QT your coral for observation if you're suspicious of something before using any chemicals.

And Congratulations on the new babies!