Yellow Sponge or Egg Mass?

[scubadiverjackcook]

I took this shot at Anacapa Island last Saturday on the backside at the sea lion colony. It was in about 25 feet of water and attached to a large rock. Is it a type of sponge, or is it an egg mass. I am told that someone else saw the same thing at Point Dume on the same day.
It was about 4 inches by 2 inches and had ribs that seemed to be filled with fine sand.

 

[Jim Greenfield]

Nudibranch eggs - don't know which nudi though

 

[Bubbletrubble]

Definitely nudibranch eggs.
Looks like the eggs of Peltodoris nobilis to me.
Here's a link to a Sea Slug Forum pic of the nudi and its eggs.

Did you see any of those Noble dorids in the vicinity?
I've seen this species all over SoCal. Hard to miss since they're big and yellow with dark pigment not on the tubercles.

 

[scubadiverjackcook]

Thanks. I didn't see any Peltodoris nobilis on my dives that day, but I have seen a lot of them lately everywhere from sandy bottoms in Newport Beach to rocky outcrops at Long Point. They seem to be pretty ubiquitous.