Nudibranchs, The Most Colorful Creatures in the World

Nudibranchs, The Most Colorful Creatures in the World

Part of the mollusk phylum, Nudibranchs are the shell-less relatives of the snail and are known for their garish colors. These tiny sea creatures are usually only 2cm - 6cm in length and can be found worldwide. They are able to thrive in any depth of salt water from the deepest darkest ocean floors to warm shallow water.

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There are over 3,000 known species of nudibranchs, and scientist estimate that only half have been discovered so far. The creatures soft-body and short life span of 1 year make it possible for many of them to live undetected and vanish from the earth without a trace.

Photo by wildsingapore

Nudibranchs are blind, and the animal relies on smell, taste and feel to navigate their surroundings to find coral, sponges, eggs, small fish, and other nudibranchs to eat.

The nudibranchs most exceptional aspect is their incredible color palettes. Some species' palettes match the dark greens and browns of their ocean surroundings, while others boldly contrast the colors of their habitats. These brilliant colors are an evolutionary development that began when they first shed their shells for other defense mechanisms; either to blend in to their surroundings with camouflage or as warning sign for any animals thinking of dining on a tasty little nudibranch, letting them know of their toxic secretions and stinging cells. As it is, some species dine on toxic sponges which alters and stores the sponges toxic compound in the their bodies and are able to secret them from glands when bothered.

Photo by wildsingapore

Nudibranchs have been studied extensively by scientist looking at their simple nervous systems for clues to learning and memory and their chemical makeup in search of pharmaceuticals.

Photo by wildsingapore
Blue dragon nudibran Hypselodoris sp.
Photo by wildsingapore

Photo by wildsingapore
Cuthona sibogae Pteraeolidia ianthin
Photo by wildsingapore

Photo by wildsingapore
Varicose phyllid Chromodoris magnific

Photo by Raymond™

Photo by Raymond™
another nudibranch Hypselodoris bullock

Photo by Raymond™

Photo by Raymond™
Chromodoris willani Glossodoris atromarg

Photo by wildsingapore

Photo by wildsingapore
Donut Nembrothas yet another

Photo by Raymond™

Photo by wildsingapore
Bornella Pteraeolidia ianth..

Photo by wildsingapore

Photo by Raymond™
Chromodoris annae

For more information and to see an amazing set of photos from David Doubilet check out this nudibranchs feature by National Geographic.

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Showing 1 - 26 of 26 Comments


What wonderful colors! Thanks for telling me about this little organism.


I want one now. :)
Slugs are awesome. Colorful things are awesome. That's, like, double awesomeness right there.
They're so prettyy. I never would've known they existed if it wasn't for this little article here. Thanks.


There was special in National Geographic last month or so about it - they were GORGEOUS. They took the little things, put them on an all-white background, and put them back. The whole thing was done underwater! They were SO pretty. It should still be on the website, if not on the front page, you can probably search for it. It's so cool that there are such beautiful creatures on this planet that we have (hopefully) not yet disturbed. And we keep finding more...


wow... these are some of the most beautiful creatures I've ever seen, wow! :D:D


mother nature is truly the most talented artist!


Interesting. I wonder what evolutionary advantage they get from the bright colors.


mmmmm yet another animal to get inspiration from.


Its a stunning bouquet of colours!

wow , thanks a lot


Wow! Those are some of the coolest creatures I have ever seen!


firecracked asked: "I wonder what evolutionary advantage they get from the bright colors."

Nudibranchs exhibit "aposematic" coloration, also known as "warning coloration". Aposematism is effectively the opposite of camouflage -- it serves to make the animal as conspicuous as possible. Another common example of this is the "ladybug" beetle. Nudibranchs, ladybugs, monarch butterflies, poison dart frogs and many other creatures have a biochemical defense that makes them toxic or just taste bad to their predators. The vivid colors are a marker that the predator will learn to associate with the unpalatability and avoid other prey of the same variety.

So pretty! I'm more than a little squeamish when it comes to anything of the slug family, but I was actually able to look at these. :P


Absolutely gorgeous! Creatures of the sea are amazing. These colors! Can't say enough.

I was similarly inspired myself recently--this pallette inspired by a 19th century book plate of sea cucumbers, close (more sessile) cousins to the nudibranchs.



How vivid and eye crackling these Nudibranchs are, the colours are so spectacular and the fact that each sub species is so different can-not be imagined.
I first learnt of these about 40 years ago and then it was only a notation about an individual 'animal' in a section about sea cucumbers. It was supposed that this one creature could change colours at will, not unlike an octopus.


I've always thought these guys were so interesting. Nice job on the article!!


My favorite article! It's what brought me to CL. I have a huge book about nudibranchs, but has a lot of information and pictures of them too, if you're craving more of the nudibranch goodness :)


stunning animals. great post. :)


Amazing! Mother nature is indeed the greatest artist.

Sarah Christenson

i love these. don't they look so soft, too like if you touched them they'd be velvety?


I wished they had a longer life span and that we could keep then in our aquarium.


wow great blog! very inspiring, not just the colors (wich are very cool) but also their shapes :) <3




Uuuwaaahhh! Wow! Stunning! Aquatic life is sooo exotic!
Splendid! So beautiful! Thanks for sharing all this in an article!
Can't take my eyes off of it! \ ( O___O)/


the designers of the animal kingdom
just like watersnails ;-)


Amazing - check out cuttlefish as well. Mesmerizing!


AMAZINGLY beautiful!!!


Wow they are indeed colorful and look amazing.

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