ID this speck please

[Capt56]

These things hang on my wall. Anybody know what they are? Ich maybe? Sea spider? Pod? Thanks in advance.

 

[LeslieH]

It's the medusa stage of a hydroid. Many cnidarians have a 2-stage life. There's the hydroid which is attached to something. These form buds which become free-swimming medusa similar in appearance to true jellies. The medusa release larvae that settle on the bottom to become hydroids. they come & go in tanks, and are harmless.

 

[mndfreeze]

Sometimes the hydroids they turn into are not so harmless. :/ Those stupid digitate ones irritate some of my corals enough to cause them not to open with their weird little fishing things.

 

[LeslieH]

Sorry, I wasn't clear enough --- it's the little jelly stage on the tank's glass that's harmless.

 

[Capt56]

Any pics of these hydroids?