Zoanthid melting

[305phins]

So my zoanthid (Jedi mind trick) wasn’t really opening just like two out of the 5 were opening. So I dipped it in coral rx waited a week no improvement. 2 days ago I tried dipping them in Lugols and now they look like this. Something coming out of the closed heads. Anyone know what it looks like or have any ideas ? Thanks

 

[Mr. Mojo Rising]

How are other corals doing? Can you tell us about your lighting and flow and parameters?

 

[EnterName]

I would say the stuff you are seeing is either:

1. an expulsion of waste and "unwanted" (e.g. dead) zooxanthellae, or
2. mesenterial filaments, which are part of the coral's digestive system. I'm not sure if zoanthids also use them as a defense mechanism and stress response like some other corals do.

Iodine dips are quite harsh on corals. That's why most products like Coral RX don't contain it. Iodine certainly kills a lot of organisms (harmful or not), but the coral and its zooxanthellae have to tolerate it as well.
In microscopy it's common to use a very dilute Lugol's solution to kill, stain, and fixate various specimens. This affects dinoflagellates like Symbiodinium spp. as well, which make up a significant portion of your coral's symbionts. Its effect is immediate and extreme, so I hope you diluted the solution very strongly before use.

Mr. Mojo Rising is already asking the right questions to figure out what the cause of the issue might be. A remote diagnosis of a "disease" is pretty much impossible, but parameter adjustment to prevent the issue from getting worse might be feasible.

 

[305phins]

Thanks a lot for the two replies. The rest of the corals for the most part look good it’s basically a zoanthid only tank. Most frags and colonies look good while a few have some closed heads. It seems every few weeks one two or three headed frag closes up and melts away. Lights are two hydra 32 on 33%intesity. Flow is good but not to strong. Parameters I’ll put in the picture but nothing seems to off. I saw one zoa eating nudi a long time ago and removed it by hand can’t find anymore and I search around at night. Seemed like another frag I had was going through the same thing but responded well to the coral rx.

 

[305phins]

Oh and I did dilute I think I used 4 drops for 500ml and it was a 13min dip.

 

[Mr. Mojo Rising]

Any reason to run the lights at only 33%? A lot of your zoa's are stretching up to the light, even at the top of the rocks they are stretching up, its a really good indication the system needs more light. My own zoa's are under pretty high lighting and they grow very well. I think this is a low light issue IMO

 

[305phins]

I was fighting hair algae for a while and it was a nightmare . And since zoas were closing and dying I didn’t think it was a low light issue. Also sometimes the zoas give that inside out mushroom look so I thought light might be a little high. Thought since they were zoanthids and I have algae it would be better to under shoot the light.