White Bulb?

[Brisc0]

I just noticed these little white blubs on my new LR (day 7) They only appear on spongey looking pieces, never just on the rock. Can anyone explain?

 

[fishfreek]

Could be a sponge of some sort?

 

[notmuffy]

When you say they live on spongy looking pieces, not on rock, are you talking about leather coral? Do these spots move (nudibranchs) or do they look like egg sacs at all?
If you had said you have 'spongy white spots ON my live rock" I would say it was definitely a sponge, I have 5 or 6 of them. But that wasn't what you said .