Zoa colony dying - funny white threads?

[timmeh]

Hey folks,

Last fall brought a beautiful zoa colony into our (15 gal) tank that did well for months, and then took a sharp turn for the worse a few months back. I just moved this colony from it's spot in the tank to a little isolation tank (since I was worried that maybe a hermit crab was picking on it), when we noticed something odd. White threads. And in fact, these white threads are also on the rock near where the colony was sitting (nearby to all our other healthy zoas which are happy as can be).

Here are the photos:

Can anyone help me understand what these white things are, and if those are the likely reason why this went from a big, thriving colony to nearly dead? And ideally, if it's still possible to save this colony!

Thank you!!

 

[Baykes]

Are they are hard or soft? Do they move? If hard they kind of look like feather dusters which shouldn’t kill the coral

 

[Turkeysammich]

I’m not a zoa guy. But I did sleep at a holiday inn last night. Lol.
Anyhoo. Freshwater dip the whole colony. Just match the water temp. 15 minutes then return the colony to the aquarium. See if that helps. If there’s bacteria or parasites. The fw dip will kill it. The Zoas will close up. Keeping them water tight and safe. Every thing else on the outside should die.

 

[derek_SR]

They sure look exactly like the little feather dusters I get, which are harmless. Guessing they are not related to the zoa issues.

 

[Invictus]

If you look on the left side of the first picture they do have a micro feather duster like extension.

Seems like some types of colonial hydroids could present similar to this, but I would guess they are micro feather dusters and not actually the cause of the zoas going downhill.

 

[timmeh]

Okay - so, good to know that the crazy-high-density of these feather dusters isn't the cause, but just a... coincidence.

I love that idea of doing a freshwater dip. I'll take some RODI water, temp-match it, and drop these boogers in for 15 minutes. If it helps stop the colony decline, then that's a big win. If they die... well, crud, that's the path they were on anyway.

And, I'll keep them in the little isolation box for a while! Maybe the culprit was a hermit crab causing trouble after all!

 

[t0mmy108]

yeah, little worms/feather dusters. Probably not the cause but don't underestimate zoanthids. They can come back from a half dead poly or even a slither of flesh. They just can't survive a long term dip in sriracha hot sauce.

 

[timmeh]

I hope so! This was my favorite colony (probably 4 dozen heads, and just completely covering the plug). And now it's nearly gone.

I'll cross my fingers the RODI dip does the trick. And, I'll probably use a toothpick to smash up some of those feather dusters just to be sure. It's just so weird that there is a huge mass of them on this plug, and the surrounding rock... but nowhere else in my tank.

 

[timmeh]

Okay, so we dipped the frag for 15 minutes in RODI, and used a toothpick to carefully scrape off all the feather dusters (just to be safe). I 3d-printed a little frag holder to move it up on the wall and away from any trouble-making hermit crabs (in the off chance the crabs are causing an issue).

Fingers crossed it'll recover.

 

[Turkeysammich]

Did anything strange fall off ?