Unusual red worm in reef - good or bad?

[WrasseyReefer]

I found this unusual red worm in my reef tank on my Trochus snail’s shell. It’s maybe an inch or less long and has red tentacles. I removed it and put it in a cup with tank water. I want to make sure whether it’s good or bad before I potentially put it back in the tank. Thanks!

 

[WrasseyReefer]

Another photo:

 

[nsteinca]

Looks like a spaghetti worm

 

[WheatToast]

Looks like a spaghetti worm

Agreed. Either a hair worm (Cirratulidae) or a spaghetti worm (Terebellidae) which are both beneficial detritivores.

 

[WrasseyReefer]

Ok so it’s a good worm. That’s great to hear. Based on google searches, that’s what I thought, but I wanted to get others opinions as well to be sure it wasn’t harmful to corals, inverts, or fish.

 

[StripeCore]

That's a spaghetti worm, It's harmless.