In conjunction with National Sea Slug Day last Monday, the
California Academy of Sciences released colorful photographs of 17
newly identified nudibranch species.
Striking colors and unusual color patterns were given a special
focus in a genetic study that is helping to group the nudibranch
species and understand how they evolved. Hannah Epstein, affiliated
with the California Academy, was the lead author on the research
paper published in the
Zoological Journal of the Linnean Society.
Nudibranchs, soft-bodied mollusks often called “sea slugs,” are
among the most ornately decorated creatures in the sea. With about
3,000 species of nudibranchs coming in all shapes and colors, I
thought it might be fun to track down some of these animals.
Frosted nudibranch //
Photo: Dan Hershman
Nudibranchs are found in all the world’s oceans, but you don’t
need to go beyond Puget Sound to find some of the most beautiful
ones. I’m grateful to Dan Hershman, a retired Seattle teacher,
part-time musician and underwater naturalist, who shared some of
his best photos of sea slugs from this region. Check out Dan’s
Flickr
website.
The word nudibranch (pronounced nude-eh-brank) comes from the
Latin word nudus, meaning naked, and brankhia, meaning gills. So
these are animals with naked gills, which often grow out of their
backs and sides. These creatures can be as small as a quarter-inch
or as long as a foot or more.
White and orange tipped
nudibranch
Photo: Dan Hershman
Nudibranchs are carnivores, eating things ranging from algae to
anemones, barnacles and even other nudibranchs. They can pick up
coloring for camouflage and even poisons from the prey they eat,
using the chemicals in defense against predators.
Hermaphrodites with reproductive organs of both sexes, these
animals don’t normally self-fertilize. But they are prepared to
mate with any mature individual of the same species. Eventually,
they will lay masses of spiral-shaped or coiled eggs.