Hi Ron,
I saw something brand new tonight. Lights were out, and I was feeding my sun coral with a flashlight to see. Suddenly I saw these very short orange worms swimming through the water. Then I saw white ones. There were probably 20 or 30 in my 55g, all scurrying through the water, swimming up to the surface... just hanging out. I did try to get some pictures, and went ahead and shot some video.
The orange guys were very thin, maybe 2mm wide, and about 5 - 6mm long. Unreal to see something like that after a couple of years of observing.
The white ones were longer, maybe 3/4" long, but just as thin. They would wriggle their bodies like a snake at high speed. And they moved relatively fast, as they swam in the water. The powerheads were all off, so there was no current to move them nor to fight against.
Here are two pictures. I'd say that they are roughly the size of a maggot.
This second picture, you can see one darting through the water right over the nassarius snail. I would never have gotten it in the picture if I'd tried, it flew through as the shutter saved this moment in time:
And finally, here's a 1 minute video so you can see these guys in action, up near the surface.
http://www.melevsreef.com/video/afterdark.wmv 5megs
I know you get a ton of requests, so let me thank you in advance. I just can't get over seeing this for the first time with so many years of night-observation on my part.