Need an ID for whats on my snails

[itis]

I recently noticed these clear bubbles attached to my dwarf cerith snails when they emerged from my sand bed. Does anyone know what it is? (algae, eggs?) I've had these snails for over a month, and this is the first time seeing these.

 

[king aiptasia]

do they move? is it halimeda algae?

 

[vetteguy53081]

Bubble algae and valonia macro

 

[itis]

Odd, I don't have bubble algae anywhere else in my tank but I'll be sure to give these guys a scrub.

Thanks for the replies.

 

[NKYReefer]

Pineapple sponges maybe. I had something similar on my glass after getting shipment of snails.