Weirdos of the Ocean: The Spanish Dancer

Janina Speck
8 minutes ago
2 min read

You know what most sea slugs don’t do? Flamenco. But one of our weirdest marine creatures has its own fabulous underwater version—and that’s why we’re talking about the Spanish Dancer.

With frilly, bright red “skirts” and the kind of moves that would win Dancing with the Starfish, the Spanish Dancer (a type of nudibranch, or sea slug) isn’t just weird—it’s dramatic.

Hand holding a vibrant red and orange sea slug with wavy edges in clear shallow water, reflecting sunlight, creating a serene scene. — A Spanish Dancer we found during a kayak tour in 1770

A little personal obsession...

Ever since I became a scuba diver back in 2002 and saw a Spanish Dancer on the reef in Utila (a little island in Honduras), I’ve been absolutely hooked. They’re not something you see every day—so when you do, it’s a bit of a thrill.

On a trip to Tonga a few years ago, a friend and I literally sprinted (in our snorkel gear) when we heard there was one in the area. After a bit of searching, there it was—our bright red prize! We snorkelled with it for half an hour, grinning like weird little kids at Christmas. I even got some video footage that I still drag out to show people when they say, “It’s just a slug.”

Snorkeler in black gear and yellow fins takes an underwater photo of a spanish dancer on a sandy seafloor in clear blue water.

And then there was this day on tour…

There was much excitement (mainly on my part 🤣) on one of our Family Tours a few years ago. When 4-year-old Kenzie spotted “something red and squishy in the water,” I had a feeling it could be one of my favourite creatures ever. I turned around, had a look, and sure enough—there was a SPANISH DANCER in the water!

Then it went like this:

ME: OMIGOD OMIGOD OMIGOD – A SPANISH DANCER!!

KIDS: What is it??

ME: It’s a type of sea slug and we don’t see them very often. It’s quite rare to spot one.

KIDS: I want to see dolphins.

ME: NOOO! LOOK AT THE SLUG!!

KIDS: But... dolphins...

ME: BUT LOOK AT THE BEAUTIFUL SLUG!! 🤣🤣

Look, not everyone gets it, especially if they are 4 years old! But if you know, you know...!

Spotting a Spanish Dancer on our kayak tour

Just how weird are Spanish Dancers?

They’re massive (for a slug)—some grow over 30cm long.
They’re hermaphrodites (nature’s multitaskers).
They lay pink, frilly egg ribbons that look like something off a lingerie sale rack.

Red sea slug eggs in a ribbon-like formation on a coral reef, set against a vibrant blue underwater background. — Spanish Dancer Eggs - photographed on Heron island

And yes, they actually swim, with big dramatic undulations that give them their name.

This Spanish Dancer footage was taken by me during a trip to Tonga

Most of the time they lie flat on the seafloor, quietly weirding it up. But when they’re startled—or feeling a bit fancy—they burst into their signature flamenco swim. It’s wild. It’s slow-motion. And it’s one of the strangest, most fabulous things you’ll ever see in the ocean.

Spanish Dancers are also toxic to predators, which is what all that flamboyant colour is about. It’s not just for show—it’s their way of saying “eat me and regret everything.”

If you want to learn more about their even weirder cousins, check out our full Sea Slugs. But this one? This one gets its own episode. Because drama.