Unknown orange ‘thing’... worm?

[william.moore]

This has been on the rock under my zoas every since I got them around 18 months ago. It’s never really caused any issues. The other day my Tuxedo Urchin ripped a patch of the zoas off and it’s made me think about it again. Any ideas what it is? Should I be worried about it?

 

[Humblefish]

I'm not really sure what that is. A medusa worm or spaghetti worm is just what comes to mind (since you mentioned 'worm').