The Strange and Magnificent Nudibranchs of the Cape

One nudi looks like an open gas flame blazing underwater.

Another one appears on the sea floor like a ghost with rabbit ears.

One looks like strings of neon noodles clinging to the reef.

Another looks like puffs of tiny white clouds.

And one even looks like a little marine rhinoceros with orange-tipped horns.

The list of things that nudibranchs resemble is endless.

These little marine slugs are so utterly strange and out-of-this world that the only way somehow comprehend their countless shapes and beautiful colours is to compare them to things that sit more comfortably in our consciousness.

A gas Flame Nudibranch: Photo by Richard Darke @RCDImages
It’s become a mini-obsession of mine. Each time I freedive in chilly waters off the coast of Cape Town, among the granite reefs and kelp forests that fringe this lively coast, I search for these little wonders, hoping to find something new.

Its strange. Nudibranchs are hard to see at first. They are tiny slug-like animals that move slowly along the sea floor, blending in with the many other purples and reds and blues of the reef. Their miracle colouring is a defence mechanism. Having shed their protective snail shells in some previous evolutionary diversion, their colours signify extreme toxicity. Stay away, they say. But it has the opposite effect on me. They are also totally mesmerising. Once you spot one and dive down close, hanging weightless above the animal, you simply cannot take your eyes away from the neon colours dancing in the light, the soft tentacle-like arms swaying in the swell.

Their magnetism can be a problem when freediving, because at some point you need to tear your eyes away and head towards the surface for a breath.

One of the ways to appreciate nudis for longer than a single breath is to look closely at photographs of them. Luckily, there are a few committed divers around Cape Town who spend hours underwater searching for and photographing nudibranchs and other marine wonders. Below are some of the most interesting contributions made in the nutrient rich waters of the Cape.

Look closely at the nudis. Get lost in their shapes and colours and see what images your mind produces. And for a moment, admire the natural wonders that our ocean produces, but are so rarely seen.


1. The Crown

A Crown Nudibranch, Photo by Richard Darke @RCDImages


2. The Ghost

A Ghost Nudibranch. Photo by Richard Darke @RCDImages

3. The Frill

Frilled Nudibranch, Photo by Richard Darke @RCDImages

4. The Medallion

Silver Tipped Nudibranch. Photo by Ben Wiid @two_oceans_one_breath

5. The Lady

A Purple Lady Nudibranch, Photo by Richard Darke @RCDImages


6. The Ink Spot

Ink-Spotted Nudibranch, Photo by Richard Darke @RCDImages

7. The Fire

White-tipped Capensis, Photo by Raoul Coscia

8. The Dark

Black Nudibranch, Photo by Richard Darke @RCDImages

9.  The Club

Orange Clubbed Nudibranch, Photo by Ben Wiid @two_ocean_one_breath

10. The Gas Flame

Gas Flame Nudibranch, Photo by Richard Darke @RCDImages

Special thanks to Richard Darke @RCDImages, Ben Wiid (@two_oceans_one_breath), and Raoul Coscia for the Nudibranch gallery.

What’s Next?  The coastal waters of the cape are some of the richest and most diverse in the world. The collision of warm and cold currents at the tip of Africa creates a nutrient rich environment supporting animal species of all sizes – from nudibranchs and shrimps up to southern right whales and great white sharks. To celebrate these natural wonders, we have put together a photo database of the Cape’s magnificent ocean animals and their habitat. Through working with local divers and photographers, we will be publishing regular galleries of the most interesting and stunning images from our Two Oceans.

If you have any images to contribute, we will be creating a regular gallery of the top images from the sea for everyone to appreciate. Please submit these to


Meet the Author
Paul Steyn is a widely-published multi-media content producer from South Africa, and regular contributor to National Geographic News and blogs. Having guided throughout Africa for some years, he went on to edit a prominent travel and wildlife magazine, and now focuses on nature storytelling in all its forms. In 2013, he joined a team of researchers and Bayei on a 250km transect of the Okavango Delta on traditional mokoros. In 2016, he accompanied the Great Elephant Census team in Tanzania and broke the groundbreaking results on National Geographic News . Contact: Follow Paul on Twitter or Instagram