Anyone have experience with these? I found a website about them while looking for info:
http://www.northern.edu/natsource/INVERT1/Hydra1.htm
I found a couple on my tank glass after collecting some local plants and not dis-infecting them.
(I can see Tex Gal shaking her finger at me and saying "I told you so!" )
I don't see them being a problem since I'm pretty certain there is nothing in my aquarium they can eat (the two I saw were 2mm in length and looked like algae until I put a 15X magnifying glass on them).
-Dave