Originally Posted by ROYAL GANG
Hey... I noticed some white spots on your rock and glass, did you notice them? Anyways, I think they might be sponges.
For real? Thats what this post is about...
As the other posters have said it is probably either snail eggs or some kind of small tube worm. A closer picture and a list of inhabitants in the tank would be the only way to get a better idea.
I agree with threed and would guess that some type of worm is what you are seeing. Do a search on spirorbid worms. They are a harmless filter feeding tube worm and pop up pretty often as hitch hikers on live rock.
I just scraped one off with my fingernail. They're pretty hard, kind of crunchy.
In the tank we have 3 Astrea Turbos, and a bunch of Nassarius and Cerith snails.