After dark there were about 12 of these...

[seahorsedreams]

Did they resemble bristle worms at all?..... any part of them? During repro BWs change into two parts..... well one part changes and the other stays the same. The atoke which is the front end (unchanged part) and the epitoke which is the back portion. Then when the time is right, the epitoke separates itself and swims to the water surface. Usually there is one that one worm participating much like you describe. They swim in a cork-screw type fashion. I have seen it several times.

I'm not sure if this is what you are seeing or not but I thought I would throw it out there.

[AuntKaren]

I've never seen a bristleworm without bristles but I've only seen about 4 of them. If you go out in your back yard, dig in your flower garden and pull out a worm....THAT is exactly what my tank worms look like! They didn't have the "ribbing" rings but there are no bristles. Seahorsedreams you could be right about them separating but we watched them for about half hour and all they did was rise up and down the tank being carried sideways by current. We did go back to bed while they were still dancing around, though. I bet they are another type of worm but your explanation of what they were doing makes alot of sense. ::Shrugs::

[seahorsedreams]

This is an enlarged version and not my picture. But the epitoke doesn't look bristley and is small so that you wouldn't notice all the spines. The top part separates from the bottom. The bottom goes "swimming" around.

[mutts]

ewww thats kind of gross, got to love the things that show up in our tanks

[AuntKaren]

Nope, Whisperer, that's not what my worms looked like they didn't even have the tiny bristles shown on the back half of your pic. I swear they looked like earthworms! I'm scouting the tank near full moon again to see if I can get a pic of them swimming or a better closeup of one out of the tank.

Boy this is frustrating! Think earthworm!! LOL

[seahorsedreams]

I wonder if something like a peanut worm would reproduce the same way?

[AuntKaren]

I'm taking the pathetic pic that I got to my LFS guy and asking him if he has any clue. My LFS guy, btw, is good friends with the guys who own Tampa Bay Saltwater they have known one another for years....I've learned to trust my LFS guy so I won't be embarrassed to post what he says. :-)

[seahorsedreams]

Can't wait to hear what he thinks.