Feather, barnacle or?

[Dew3600]

Lately one of our corals has been staying closed and we weren't sure why but with it being closed, today I noticed a feather duster and this thing that kind of looks like a feather duster but is different from any feather duster I have seen! It reacts to movement just like a feather duster would. It's sort of in the middle of this colony. Thanks in advance

 

[Stealthreefer]

It's probably been there as long as the coral and I can't' think of a single time I have had those cause problems. Certainly not with GSP.

 

[Reef By Steele]

The picture of it is kind of hard to see. Does it have a tube? And a little thing protrudes?

 

[Dew3600]

The picture of it is kind of hard to see. Does it have a tube? And a little thing protrudes?

Not that I was able to see but it could, its tangled in the middle of this colony thats covering 4 or so loose rocks otherwise id remove the colony for a better look. It's tiny. It also extends pretty slowly, any videos I've seen of barnacles their little fan thingys move pretty dang quick. It retrects quickly when I get near it though. I never see it retact unless I scare it.

 

[Reef By Steele]

I was just wondering because when I zoom in it kinda looks like a vermetid snail, but they grow from a hard slender tube.