Sea Lemon Nudibranch is a common visitor to our local rock walls (like Sund
Rock). They are bright yellow and grow to about 10" long. The top is covered
with short, rounded projections and a ring of 6 white-edged, frilly gills can be
found near the back end. They live at depths from tide pools to about 750’ and
range from British Columbia to Baja California.
This is one of the largest species of nudibranchs along the Pacific Coast. It
feeds entirely upon sponges, and prefers the yellow Halichondria (Bread Crumb
Sponge), which is where it gets its color. The Sea Lemon emits a strong, fruity
odor which seems to discourage predators, and is where the name originated.
Because of the structure of its nervous system, this sea slug is often
utilized for neurophysiological experiments, which has enabled researchers to
mimic the workings of the human nervous system.