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!