Nudibranchs are hermaphroditic. These two, the larger about 60 mm long, are mating, right shoulder to right shoulder, exchanging sperm. Later they each will lay an egg ribbon. Depth 12 m.
These dorids are feeding on the underlying Membranipora bryozoan. Also, their orientation, right shoulder to right shoulder, suggests that they are mating. Both species are commonly found on blades of giant kelp as seen here.
This closeup of the head shows the rhinophores. Note also that, although this species generally does not have orange spots on the dorsum, a few small scattered orange spots can be seen here on the head.
This view of the posterior dorsum shows the ring of short, white gills and also the network of spicules below the skin surface that can often be seen in this species.
