Featherduster?

[needlehandssoftfingers]

I can't get a good angle to see down it's tube, but it seems like it also could not be a featherduster based on its tentacles? Still newbie

 

[MelancholyBlenny]

Feather duster

 

[WheatToast]

Fan/tube/feather duster worms. Harmless filter-feeders. You can see the elongated tube of another one in the background.
https://content.invisioncic.com/Mna...2663.jpg.10d406c5ba318f8e59343b540ad50730.jpg

 

[jmichaelh7]

I have millions of these … not sure if I can ever eradicate them. They cover my sump equipment. Seem harmless for sure

 

[vetteguy53081]

Yep - tube worm which catches fan to capture food often favoring Brine shrimp