The World's Most Beautiful Slugs
By Susan Boac
Published: 06/23/2013  Updated: 08/08/2019
Opalescent Nudibranch in a tidepool on the Oregon Coast.
Opalescent Nudibranch in a tidepool on the Oregon Coast.  Photo by Gary Hayes

Look closely in tidepools or on intertidal rocks at low tide and you may find one of several varieties of slow moving nudibranchs, often called sea slugs.

The name nudibranch (pronounced noo-duh-brank) refers to the animals' exposed gill structure or "naked gill." There are many varieties you might see including the common, but brilliantly colored Opalescent Nudibranch with orange hair-like projections (pictured top), the bright yellow Sea Lemon (bottom left) or the gray-brown Sea Mouse (bottom right). On a really lucky day you might discover the exotic spotted Leopard Nudibranch or the Clown Nudibranch decorated with orange dots. These aren't your average garden-variety slugs and can also be found in ocean depths of over 200 feet!
The World's Most Beautiful Slugs