We just had something similar looking in our tank, ours were bristle worms and the guy at the reef store said to remove them with long tongs and to NOT touch them with our hands because they would leave little hairs in the skin and can be pretty painful. He said they were BAD for the tank and I needed to get them out ASAP.
They're actually a great part of the CUC. some people don't like them, but I've seen huge ones in some of the best SPS tanks. They aerate your sand, eat detritus, and other good stuff that reefers like.
Older thread but wanting to know others experience on fire worms not bristle I have plenty of bristles in my tank and have no issues with them.
Last night while Santa was putting presents a dang turbo had flipped over in the tank. I also have a few empty shells for crabs to switch to if needed.
When I had the pinchers in going to right the snail I saw what I think was a fire worm did not look like any bristle worms I have seen in the tank before.
As soon as I got the pinchers close he quickly hid in one of the empty shells I had in the tank. So I quickly grabbed the "empty" shell and took it out of the tank and ran to the kitchen for a Tupperware bowl.
I put the "empty" shell in there and took it the other room. I tried to empty the shell of the water to see if it would leave the shell in look for water. Watched the shell for about 5 minutes nothing.
Being that it was getting late and I did not want to kill the thing without knowing what I was dealing with I put some more tank water in the bowl and put a shrimp pellet in with it.
Another 5 minutes went by and nothing I know I should have watched it longer if I wanted to see it, but at this time it was already 11:30 and I knew the youngest would be up in what would seem like a couple hours.
So went back to the tank and finally saved the poor snail and went to bed.
Been looking in the bowl every once in awhile to see what comes out and nothing yet. Half of the shrimp pellet is gone so I think I got him.
So after all that my question is if it a fire worm. Where there is one is there more?
I will post a picture if I ever catch him out of the shell but you know how that may go it could take days to catch him out again.