This is the largest of California nudibranchs. It has a penetrating, fruity odor, which may be used to fend off predators. It feeds on a variety of sponges, including Axocielita originalis
, Astylinifer arndti
, Hymenamphiastra cyanocrypta
, Lissodendoryx firma
, Halichondria panicea
, Haliclona permollis
, and species in the genera Mycale, Zygherpa, Parasperella
, and Prianos
. It may also ingest quantities of organic detritus. Studies show that individual nudibranchs are conservative in their food habits; they tend to keep eating the same food species, even if they are transferred to other sites. Spawning period varies with location, but extend for several months. The mating is reciprocal; partners may be of vastly different size. This species is a simple organism to study the nervous system and thus has been used for much neurophysiological research.
Sponges which live on the motile scallop Chlamys hastata are less vulnerable to predation by this nudibranch.