White nasty in tank

[enigmatic]

Hi,

I was looking at the tank last night ahead of a water change and noticed a small white nasty of some description moving on the glass.

I'm guessing this is some kind of parasite that has come out of one of the fish . I'd be grateful if you could help confirm what it could be so I can treat the tank properly.

I've drawn a picture as best as possible (not really my thing) as I couldn't get a photo of it. Very small, probably 3-4mm long. Body was white and thickest part with several "arms/legs" protuding from the end.

Thanks in advance for your help.

Chris

[ILLUSN]

sounds like hydra to me, is this them?
http://www.discusforums.com/forum/viewtopic.php?p=102243&highlight=hydra#102243

[Merrilyn]

Definately Hydra. Nasty little things.

A real danger to fry, but not much of a problem to larger fish. They will be feeding off small food particles in the water, especially things like baby brine shrimp and small daphnia.