Biology/Natural History: Feeds on yellow crumb-of-bread sponge Halichondria panicea, as well as other sponges. Animals are simultaneous hermaphrodites, lay eggs throughout the year. Non-motile sperm from partner is stored in a seminal receptacle for some time before the sperm become motile and fertilize the eggs as they are laid. Eggs are in capsules of several eggs each, which are then formed into a narrow cord which is folded into a bright yellow or cream gelatinous ribbon of about 2 million eggs. The ribbon is attached in a coil by one edge to a hard substrate. Egg masses exposed to the light have higher mortality rates. Eggs hatch in 20-25 days, trochophore larvae settle within about 2 hours of hatching.

Sponges which live on the motile scallop Chlamys hastata are less vulnerable to predation by this nudibranch.