Coolest Sea Animal: Nudibranch

Meet the nudibranch, one of the ocean's most colorful creatures. These soft-bodied marine gastropod mollusks boast unique shapes and colors. Found worldwide, from the tropics to Antarctica, nudibranchs (NOO-di-branks) are a diverse group. With many types to discover, this list and photo gallery will showcase their variety. The name 'nudibranch' means 'naked gills' in Latin, referencing the naked gill on their back. As hermaphrodites, they lay eggs in a gelatinous spiral but cannot self-fertilize. Unlike sea cucumbers, nudibranchs - sometimes called 'sea slugs' - are more exciting, with most not actually related to true sea slugs. Ranging from less than an inch to almost two feet long, nudibranchs have defense mechanisms like toxic appendages, camouflage, and chemical production. Explore the many types of nudibranchs and discover the most beautiful ones in the ocean.