Freshwater feather duster?

Question

I am not to familiar with freshwater tanks since I mostly do salt, but I looked into our 55 gal. and saw a thin white line with small open fans along it. It was very small but there was about 6 fans along the line and they open and close when fish swim by. I have never heard of this before anyone know what it is?

Answer 1

It's sounds like you are looking at a bryozoan. See drawings:
http://en.wikipedia.org/wiki/Bryozoan

Even better - this has photos:
http://ebiomedia.com/gall/micronat/bryozoan.html