Tube-like living organisms? a danger?

[Tigerbarb]

A while ago, I noticed a small transparent thing with a purple tint, that had tentacles that somewhat looked like those of an anemone on the wall of my tank.
When I touched this on the tentacles, it closed up quickly. A few minutes later it was gone.
Earlier today, I found an even longer one of these things on one of the top leaves of one of my plants, and it looked as though it was spreading tentacles out to eat particles of old food/trace elements. I was worried about it, so I snipped it off. It came off along with a fragment of one of the leaf it was on.
In the snipping process, It was hard to cut and it curled up. The last I saw of it was it curled in a ball, still stuck to the leaf fragment.
Any clue what this is? I wasn't able to snap any pix. Is this a danger to my fish at all? What should I do to get rid of it?

[cocoa_pleco]

its harmless. i cant remember what its called but they naturally come on plants and rocks from streams, they are only a danger to fry

someone think of the name, its gonna bug me all night

[siymdapolio]

:19: :19: ooo I want one!!

[cocoa_pleco]

they spread fast, theyre like tiny white clearish anemones, its gonna KILL ME if someone doesnt remember the name

[Fishalicious]

Hydra :19: They are harmless but can become a pest and take over the tank... they are indeed a danger to smaller fish & fry

[Algenco]

hydra are very difficult to eradicate,I've been fighting them for over a month

[cocoa_pleco]

man, it killed me all night and 5 minutes ago hydra just popped into my head.

yeah, theyre harmless, ive always wanted some.

[Tigerbarb]

So how can I get rid of hydra? Just in case my fish ever mate and the hydra become a danger to the fry...

[cocoa_pleco]

if i remember copper meds work, or you can remove the rock theyre on and dip the rock in hydrogen proxide and rinse the rock after

[siymdapolio]

Yea burn those buggers! But i sitll want some of these

[Incredulous_Ed]

I HATE hydra. I wuld have has a very sucessful batch of zobra danios but hydra killed all but 10.

[Levi]

i think it's fascinating how Planaria and Hydra seem to appear out of thin air

i once tried to get a small tank cycling by putting a small amount of fish food every few days

it didn't cycle the tank, but i got lots of Planaria

[aquarius56]

Well....I don't think I want any of those :) Everything has a right to life...even icky ones...lol...Doesn't sound like it's hard to get rid of them, though, if that's what you want. Different strokes for different folks...