Help ID

[Taruk]

I don't have a picture, but I will try and describe it. I have some critters that hang out in my LR and send out long, clear, stringy tentacles. These tentacles collect sand grains to build tube-like structures. I haven't actually seen one, just the tentacles. I have a couple of books on corals, but still shy on reef literature in general, so nothing to use for reference. I don't even know what to search for on the boards. Any ideas what these could be and are the beneficial or a pest?

 

[aquarist=broke]

Non scientific name is spaghetti worms.

I have lot's of 'em, and I watch them pull missed food into their "tubes". That right there sounds like they are NOT pests.

 

[acroman]

Ive got tons of 'em and they dont sting anything. However, brains and acros will grow around them, and it bugs gsp's. My Six-line wrasse picks on the worms whenever he sees them, but I havn't seen him get one yet.

 

[Taruk]

Yep that looks like what I have. Glad to hear they aren't pests, because I can't imagine how to remove those guys without a total tank tear down. Thanks for the replies.