What is this growing next to my Zoas?

[HenryF]

I have noticed a white little circle or spiral on my Zoa frag. I’m not sure what it is and would appreciate any information or advice on it. Thank you!

 

[cloak]

Spirorbid worm. (harmless filter feeder)

 

[Crabs McJones]

I have noticed a white little circle or spiral on my Zoa frag. I’m not sure what it is and would appreciate any information or advice on it. Thank you!

Most likely spirorbid worm, might annoy your zoas but otherwise harmless

 

[Maggie321]

Could that be a vermatid? It is bigger than my spirobids...

 

[HenryF]

Could that be a vermatid? It is bigger than my spirobids...

As far as I can tell nothing has come out of it, but I will keep an eye on it. Thank you ! Here is a “better” picture.