need ID

[GinKu]

i need an ID. i'm not sure what this is
thanks in advance
http://i47.photobucket.com/albums/f174/ginkusan/th_unknown.jpg (http://i47.photobucket.com/albums/f174/ginkusan/unknown.jpg)
http://i47.photobucket.com/albums/f174/ginkusan/th_P2144399.jpg (http://i47.photobucket.com/albums/f174/ginkusan/P2144399.jpg)

[capncapo]

Looks like a Hydroid Jelly. Is it on the glass or is it on a "stalk"?

If it's on a "stalk", it's a hydroid. If it has no "stalk", it's a Hydroid Jelly.

[kmk2307]

How many tentacles does it have? If you see more than one, do they all have the same #?

[sugartooth]

Will these turn into small "aiptasia" like hydroids? Except the stalk is very plump and fat, and the "tentacles" are very short, thin and feathery? The whole thing looks white or translucent.
I suddenly have 30-40 of them after seeing spots on the glass that look like the first picture. They are in my seahorse tank and I am concerned that they will sting the seahorses.

[Travis L. Stevens]

This type of hydroid is different then the Colonial Hydroids. Often, these will have a population boom and then subside. I wouldn't worry much about them. Just scrape your tank like you normally would and they should come right off.