Down in the dark depths of the sea lives a creature with a translucent body, tube feet that resemble antennae on its head, and an appetite for decomposing things. Scotoplanes globosa, also known as sea pigs, are a type of sea cucumber that feed by way of their face tentacles as they stroll along the ocean floor. According to this video by WIRED, the sea pigs are like "living vacuum cleaners," and their meal of choice is often whatever is dead and available.

Swedish zoologist Johan Hjalmar Théel first discovered sea pigs over a century ago, as one of around 65 new species he described in writings about a four-year research cruise around the world aboard the HMS Challenger from 1872 to 1876. Since then, researchers have learned that the creatures congregate around dead whales and other sunken corpses and dine on the decomposing flesh. They also know that sea pigs cannot fight back against predators, as WIRED reports. Instead, they have toxic chemicals in their skin that deter predators from wanting to take a bite.

Still, there are other factors about the sea pigs that remain a mystery for now. Because the creatures have fragile, water-filled bodies that often turn into a liquid-like material, they are difficult to study. Scientists don't know how long sea pigs live or how they mate, but they do know how they help other sea creatures.

Marine biologist David Pawson of the Museum of Natural History said that when the sea pigs eat mud from the ocean floor, they take the nutrients from it and poop out the rest.

"They’re like earthworms," he said. "They sort of process the deep-sea mud and make it livable for other animals because they’ve increased the amount of available oxygen in it."

Learn more about the scavengers in the video above.

[h/t WIRED]

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