The film debut of the Southern Ocean deep-sea swimming cucumber, dubbed the “headless chicken monster”

A “headless chicken monster” also known as a “Spanish dancer,” captured on video in the Southern Ocean.
A “headless chicken monster” also known as a “Spanish dancer,” captured on video in the Southern Ocean.
Image: AAS/screenshot
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While we dream of exploring the wonders of outer space, closer to home, Earth’s oceans remain full of mysteries, some of which are revealed to us accidentally.

Take Enypniastes eximia, for example, a deep-sea swimming cucumber never before seen in the waters of the Southern Ocean (though filmed in the Gulf of Mexico last year). Scientists with the Australian Antarctic Division (AAD) in marine conservation efforts captured the creature on film with an underwater camera system developed for commercial long-line fishing. The super-durable cameras are now being used by marine biologists to learn about the kind of sea life that might be disrupted by commercial activities. And they are leading to amazing new discoveries.

“We needed something that could be thrown from the side of a boat, and would continue operating reliably under extreme pressure in the pitch black for long periods of time,” the AAD’s chief, Dirk Welsford, explains in a statement. “Some of the footage we are getting back from the cameras is breathtaking, including species we have never seen in this part of the world.”

Examples of Enypniastes eximia were filmed last year in the waters off the coast of eastern Mexico; using the specialized cameras, marine biologists learned that the species also swims in the seas off East Antarctica. The unusual creature has been dubbed the “headless chicken monster,” although more generous observers also call it the “Spanish dancer.” The latter moniker is a reference to its unique abilities—it doesn’t hang out on the ocean floor like more than a thousand other species of sea cucumbers, but gracefully glides upward, swimming using fin-like structures that help it evade predators.

The translucent pink Enypniastes eximia is unusual for many reasons. Its internal organs are visible, especially in youth—the young creatures tend to be a paler pink and get darker with age. It’s bioluminescent, emitting light light from its podia (feet), tentacle tips, and various other points around the body. It’s got 12 interconnected podia, forming a kind of veil, that serve as suctions to help it wander along the sediment of the ocean floor. And it spends most of its time swimming, according to a study in Journal of the Oceanographical Society of Japan.

The Spanish dancer also has an incredible tactic for turning its predators into prey. When a predator attacks, Enypniastes eximia marks its would-be eater with a cloud of glowing tissue. This makes the sea cucumber’s predator more visible and conspicuous—although it comes at a cost to the Spanish dancer. It takes up to five days for the sea cucumber to regenerate its skin and bioluminescence after an attack.

Given how glorious and strange the Enypniastes eximia is, it seems unfair to call it the “headless chicken monster,” especially since the creatures aren’t just wondrous and weird. They serve an important purpose. The world’s 1,250 species of sea cucumbers are also the oceans’ vacuum cleaners. Though “headless,” they keep coral reefs and sea-grass beds healthy by simply breathing, eating, and excreting. That is more than can be said for humans.