little white rings of death?

[jehudson]

Hey folks ... I noticed a bunch of little white rings (tiny) on some of my rock. I tried to take a picture but ended up with little white blobs. They are almost perfect circles. The center of the rings are bout the size of the tip of a pin. What are they?

[jehudson]

Keine Ahnungen?

[erikharrison]

They are probably tiny snails?

[rocknrollgirl]

I have the same thing and I have been wondering what they are as well. I have some growing on the glass on the back of my tank as well. I figured they were some kind of snail..

[jroescher]

Feather Duster worm. You have to look really really close to see the crown sticking out. They are completely harmless.

Pileolaria sp.
or
Spirorbidae

http://www.advancedaquarist.com/issues/aug2002/invert.htm

http://www.wetwebmedia.com/polychaetes.htm

[jehudson]

[quote=jroescher;584181]Feather Duster worm. You have to look really really close to see the crown sticking out. They are completely harmless.

Thanks for the links John, they were very helpful. They do resemble the picture below, however, they don't swirl. The look like tiny doughnuts. Is that how they start out?
http://www.advancedaquarist.com/images/aug2002/Pileolariawide.jpg

[Dee]

Amazing. Some of these came in on some rock I got from someone also. They spread quickly, but then started to slow down. I think the snails and crabs eat them because of their size. I was concerned at first also...thought they were a type of barnacle or something. I noticed the amount died down and nothing was dying from them. Excellent thing to know though!!!

Dee

[jroescher]

I don't have any to look at any more, and I don't remember how they started out. I do remember that they were hard to see the feather, and any movement around the tank caused the feather to suck in.

When my tank was fairly new I had thousands of them all over the back and overflows and some on the rocks. They eventually went away. I don't know if it was just a cycle, or something ate them like all the other feather dusters I've had. If I look real close I can see a very very tiny ones, but they are few and far between.