Any Idea What It Is?

[philjo]

Hi all

Found this on the front glass today. only about 2mm across.

Any idea wha it is?

Cheers
Phil

 

[jrgilles]

Its a hydra. At one point when my tank was new, I had them all over the glass, then they disappeared. Had em for maybe a week or 2, a month or 2 after I set up my tank.

They are tiny cnidarians. Don't think they are an issue. They might be able to sting though.