An unusual sea slug with a large hood, a tail with fingerlike projections and glowing bioluminescence has been found living off the West Coast of the US.

Scientists uncovered the "mystery mollusk," a strange glowing sea creature lurking in the ocean's midnight depths.

In a fascinating video, researchers have revealed a new and bizarre see-through species of sea slug floating around the midnight zone of the deep sea. Nicknamed the "mystery mollusc" by the scientists,

Monterey Bay Aquarium Research Institute (MBARI) scientists said in a press release on Tuesday that while Bathydevius caudactylus is classified as a sea slug, it was nicknamed the "mystery mollusk" because the creature was unlike any other that’s been ...

MBARI researchers have discovered a remarkable new species of sea slug that lives in the deep sea. Bathydevius caudactylus swims through the ocean's midnight zone with a large gelatinous hood and paddle-like tail,

It's named Bathydevius due to its "devious" nature that fooled the scientists at first, while caudactylus refers to the dactyls -- the fingerlike projections on its tail.

“Only recently have cameras become capable of filming bioluminescence in high-resolution and in full color,” Haddock added. “MBARI is one of the only places in the world where we have taken this new technology into the deep ocean, allowing us to study the luminous behavior of deep-sea animals in their natural habitat.”

More than two decades after spotting a mysterious, gelatinous, bioluminescent creature swimming in the deep sea, California researchers this week announced that it was a new species of sea slug.