Deffinatly not a snail. It has no shell at all. The line down the center of it's back. It opens like flaps or wings making it look like a nudi, only when you touch it. When it moves it folds them back up as moves along. It looks alot like Elysia ornata on page 333 of Shimeks book, but it doesn't have the black lines (maybe because it's young?)
Sea Hare... See here... I said..it's da easta bunny!!
Linda.. cool pic. What is it? It does look like Darren's visitor somewhat.
Darren... I figure..if you found one, you probably have many more you can't see yet. Time to figure it out and take action. If you find they eat zoanthids, bag em and send them to me!
I think I narrowed it down to some type of Elysia or Thuridilla. Both are diatom/algal grazers (sorry Dave) I sent some pics out to a couple different id sites, we'll see if they respond. Most of the Elysia are supposed to be Bryopsis eaters...
I'd love to...but I can't remove them myself. They are in the tightest spots, and even after scraping them off, they grow back. Believe me, any and all zoas and shrooms that I could reach, I yanked.