Looking at it closely, and looking through Julian Sprung's Corals, I'm thinking that it may be some sort of coral...still waiting for ideas...Have an interesting something on a strip of zoanthid...6, tiny black spherical, bubble-like things...all in a clutch...each has a dot in the middle of the top...seems more of less solid...total size of the group is about 1/2"...eggs of something?...tunicates? sponge?...anemone?...can't get a picture because too small and camera to lousy...any ideas...
I don't have any nudibranchs except for tiny glass slugs...snail eggs are a good possibility...although I'm not sure what they look like...The description is too vague. It would pure speculation as to an accurate ID.
I could speculate that you're seeing Zonathid eat nudibranch eggs vs snail eggs.
Sorry
