ID?

[Shackleton]

On the glass, just below the surface, about 4 mm across. What is this? Sponge, maybe? Thanks!

 

[NanoDJS]

I would say egg spiral . most likey form a nudibranch

 

[Bob Loblaw]

Snails operculum.

 

[vetteguy53081]

Looks like egg pattern of berghia nudibranch

 

[Shackleton]

Thank you! Removed. I’ve been having a nudibranch problem with my zoas. Now I know what to look for.

 

[DSC reef]

Snails operculum.

Agreed, not snail eggs.