A little spiral on a rock, an odd looking thing, a bright white against the reds and yellows of the sponges. I spotted the spiral from some distance away across the cave. But I know what to look for, sweeping the rock with my dive light.
The nudibranch themselves are nearby, on the same face of the rock. I find three white-margin nudibranch, two quite large at about 3cm, the largest I have seen this species. A much smaller specimen is close by, less than half the length of the adult. These are a handsome species, always nice to find.
I am surprised that the eggs are not quickly eaten by fish or other predators. There must be some defense mechanism in play, a foul taste, a toxin, nudibranch are known to employ such tactics.