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Spanish Dancer: Facts About the Dancing Nudibranch

Spanish Dancer: Facts About the Dancing Nudibranch

Written by Scuba.com
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Published on June 8, 2023
spanish dancer
TAGS: sea slug

The Spanish Dancer sea slug is a captivating creature that enchants divers and marine enthusiasts with its vibrant colors and graceful movements. Residing in tropical and subtropical waters, this magnificent species exhibits a range of fascinating traits that make it a true marvel of the underwater world. From its impressive size to its nocturnal feeding habits, and its stunning defensive displays, the Spanish Dancer sea slug never fails to captivate both scientists and nature lovers alike.

spanish dancer
Image via Shutterstock

What is the Spanish Dancer?

The Spanish dancer, scientific name Hexabranchus sanguineus is a form of nudibranch or sea slug. Its scientific name Hexabranchus sanguineus literally translate into six-gill blood colored, which describes its six Christmas tree-like exposed gills, and its deep red blood-like body coloring.

Characteristics

This amazing species can grow to a maximum size of about fifteen inches, and has been recorded in some rare instances to grow even larger.

Behavior

Unlike other nudibranchs that move by crawling, the Spanish Dancer gets its name from its ability to swim, in an undulating motion, using its red “skirt” which waves about and unfurls as it propels itself through the water. The motion looks very similar to an exotic flamboyant flamenco dancer. While it mostly prefers to crawl along the reef like other nudies, the dancer will unfurl it “skirt” and propel itself into a swim usually when it feels threatened.

While the Spanish dancer is capable of crawling across the sea bed, rocks, and corals like its other bare-gilled brethren, its ability to swim through the water column is how its common name came to be. The mantle of the Spanish dancer has wide, furled edges, which roll up close to the body when crawling. When it swims, these edges, called parapodia, unfurl and undulate rhythmically, propelling the Spanish dancer gracefully through the sea. When it is swimming, its body closely resembles the skirts of a flamenco dancer, twirling in a hypnotic fashion that few are able to take their eyes off of once they see it.

Habitat

Found throughout the tropical Indo-Pacific and the Red Sea, a yellow variant of this flamboyant nudibranch does exist, which would certainly heighten the thrill of sharing space with one of these magnificent creatures beneath the surface of the sea.

Diet

Like all nudies, the Dancer is carnivorous and feeds off sponges, and hydroids like the Portuguese man-o-war and is resilient to their toxins.

Life cycle

Most nudibrachs lay eggs in a ribbon shaped rose pattern on rocks and coral which are white or blue in color, however you can instantly recognize the eggs that belong to a Spanish dancer’s which will look like a red rose, lodged on a rocky outcrop. The eggs of this creature are crimson red and highly toxic, containing a greater concentration of poison than the adult of the species.

spanish dancer
Image via Shutterstock

Facts About the Spanish Dancer

It grows up to 16 inches

The Spanish Dancer sea slug can reach an impressive size of up to 40 centimeters (16 inches) in length. Its body is elongated and flat, with a wide and ruffled mantle that resembles a flowing dress, hence its name.

It’s a nocturnal slug

The Spanish Dancer sea slug is nocturnal and spends its days hiding in crevices or under rocks. At night, it emerges to feed on sponges, which are its primary food source. It uses its rhinophores, sensory organs located on its head, to detect chemical cues and locate its prey.

It “dances” as a defensive mechanism

One of the most remarkable features of the Spanish Dancer sea slug is its unique defensive behavior. When threatened, it can swim rapidly by undulating its entire body in a mesmerizing rhythmic fashion, resembling the movements of a dancer. Additionally, it displays vivid red, orange, and pink colors to warn potential predators of its toxicity, as it contains toxic compounds obtained from the sponges it consumes.

Conclusion

It is easy to get obsessed with sighting a Spanish Dancer. Many scuba divers or snorkelers will often go in search of these creatures, and underwater photographers simply can’t get enough of them. Watching the dancer perform is one of the great underwater experiences, which leave one simply fascinated.

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Our team of experts and scuba diving pros at Scuba.com share their knowledge of the underwater world.