Category: Sea Life

One of the most widely varied members of the animal kingdom, there are over 2,300 currently known species of nudibranch! Nudibranchs are enormously diverse, and can come in such wildly distinct, colors, body forms, and sizes that it’s hard to find two that are similar.



Scientific & Common Names

Kingdom - Animalia

Phylum - Mollusca

Class - Gastropoda

Clade - Nudibranchia


Found in oceans all around the world, the nudibranch can be found skimming the ocean floor looking for sponges and similar animals to eat. Some types of nudibranchs can grow up to two feet long!


Nudibranchs are hermaphroditic, meaning that each animal possesses both male and female reproductive organs. However, since they cannot self-fertilize, two nudibranchs are required to breed.


Most nudibranchs crawl over the ocean floors, sensing the world around them with their head tentacles and structures called rhinophores. However, there are a couple of species that swim in the water column itself. It has been observed that at least two species of nudibranchs produce clinking sounds that can be heard by humans.


Although nudibranchs are sometimes confused with sea slugs, the two are not actually closely related. As indicated by their often bright and vibrant colors, many nudibranchs have developed chemical defense mechanisms. Unlike most species, however, nudibranchs do not produce their own chemical defenses, but instead obtain them from their food sources. Sponges, the primary source of nourishment of the nudibranch, often contain poisonous chemicals in their tissues. Astoundingly, after consuming a sponge, nudibranchs are able to recycle those poisonous chemicals and use them to deter predators from eating them!

Present status

Nudibranchs are some of the most highly varied creatures in the sea with over 2,300 different species recognized. As a whole, their group is not in danger of becoming extinct. They are found worldwide, and while most prefer a shallow reef habitat, some have been found as deep as 8,000 feet.