Tiny tenticle thing on glass?

[An_Enemy]

Turned on the lights this morning and saw this thing on the glass. Is this a tiny Anemone?

 

[Retro Reefer]

Probably a hydroid

 

[samnaz]

Looks to me like Hydroid Medusae
https://www.lionfishlair.com/hitchhikers-guide/hydroid-medusa/

 

[Lovemyreef2015]

Looks more like a aiptasia from the picture.

 

[KJ]

^^^Agree!

 

[Nem0]

OMG! i found the same thing in my tank, about 5 of them on the glass/back wall!! i tried taking a picture but my phone would not focus well.

i googled both hydroid medusa and aiptasia, mine looks a bit more like hydroid medusas. can anyone explain the difference /how to determine which is which? also, any negative effects either may bring?

 

[reef lover]

Hydroids tend to look more snowflakish...and i wouldnt worry about that type they go on thier own. But aptasia...the glass anemone i would remove, kill, smother...any means necessary to remove.