Experts say the creature looks just like a floating buttocks.
Deep beneath the ocean’s surface, in the Midnight Zone where no sunlight reaches, scientists have discovered a peculiar creature.
Known as the pigbutt worm, Chaetopterus pugaporcinus was first spotted in 2001 off the coast of California. This translucent, marble-sized blob immediately baffled researchers.
Its rounded shape and distinctive lobes earned it the humorous nickname, as it amusingly resembles a pig’s behind. Marine biologists have since identified it as a type of bristle worm, though its exact life stage—whether adult or larval—remains uncertain. Unlike most of its relatives, which burrow into the seafloor, this worm floats freely in the water column, showcasing an unusual adaptation known as neoteny, where juvenile traits persist into adulthood.
Beyond its quirky appearance, the pigbutt worm possesses remarkable survival skills. Scientists have observed it generating mucus nets to trap marine snow and organic debris for sustenance. Even more astonishingly, it glows in the dark—flashing blue bioluminescence when disturbed, while its mucus net sometimes emits green light, likely as a defense mechanism against predators.
Decades after its discovery, this deep-sea enigma continues to fascinate researchers, serving as a reminder of the vast, unexplored wonders of the ocean. As marine biologist Rebecca Helm puts it, studying the deep sea feels like planetary exploration—proof that some of Earth’s most alien creatures are right here in our own waters.
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The pigbutt worm is an unusual little worm discovered by MBARI researchers.