Weird Nature

The Coolest Sea Animal You've Never Heard Of: The Nudibranch 

Ranker Science
Updated June 12, 2019 163.1k views 27 items

What's a nudibranch, you ask? Only one of the most colorful sea creatures in the earth's vast oceans. These soft-bodied marine gastropod mollusks display some of the most unique shapes and colors in the sea. A diverse group of creatures, nudibranchs (NOO-di-branks) have a habitable range that spans everything from the tropics to Antarctica. There are many different types of nudibranchs found all over the world, and this list and photo gallery will help you appreciate the many different kinds.

In Latin, nudibranch means "naked gills," an appropriate name as many nudibranchs breathe through an actual naked gill, located on its back. Nudibranchs are also hermaphroditic, but they cannot fertilize themselves, and they lay their eggs within a gelatinous spiral.

Much more exciting than say, a sea cucumber, these colorful little guys are sometimes called "sea slugs" - though the name hardly does justice to their beauty, and most sea slugs aren't actually related to nudibranchs. Nudibranchs vary in size from less than an inch to as long as almost two feet. They have many exciting defense mechanisms including toxic appendages, camouflage, and the ability to produce their own chemicals.

How many types of nudibranchs are there? What is the most beautiful nudibranch? This list features the most gorgeous nudibranchs types in the ocean.

Berghia Coerulescens
Berghia Coerulescens is listed (or ranked) 1 on the list The Coolest Sea Animal You've Never Heard Of: The Nudibranch
Photo: Parent Géry/Wikimedia Commons/Public Domain
Ceratosoma Ingozi - 'Inkspot Nudibranch'
Ceratosoma Ingozi - 'Ink... is listed (or ranked) 2 on the list The Coolest Sea Animal You've Never Heard Of: The Nudibranch
Photo:  Wikimedia Commons (CC-BY)
Miamira Sinuata
Miamira Sinuata is listed (or ranked) 3 on the list The Coolest Sea Animal You've Never Heard Of: The Nudibranch
Photo: Chad Ordelheide/Wikimedia Commons/CC-BY-SA 3.0
Flabellina Iodinea - 'Spanish Shawl'
Flabellina Iodinea - 'Sp... is listed (or ranked) 4 on the list The Coolest Sea Animal You've Never Heard Of: The Nudibranch
Photo: Ed Bierman/Wikimedia Commons/CC BY 2.0