Scientists discover glowing 'mystery mollusk' in deep ocean's midnight zone

By Gizem Nisa Cebi

ISTANBUL (AA) - Scientists have identified a new species of bioluminescent sea slug, Bathydevius caudactylus, in the deep ocean's midnight zone, stretching between 3,300 feet (1,000 meters) to 13,100 feet (4,000 meters) below the surface, according to a new study.

Researchers at the Monterey Bay Aquarium Research Institute (MBARI) said that this mysterious creature, nicknamed the "mystery mollusk," has a unique combination of features that left scientists both intrigued and astounded.

For over two decades, MBARI scientists have been on a quest to decode the natural history of Bathydevius.

"We’ve invested more than 20 years in understanding the natural history of this fascinating species of nudibranch," said Bruce Robison, MBARI’s senior scientist.

Their efforts culminated in a recent study published in Deep Sea Research Part I, describing the species' unusual anatomy and behavior.

Unlike other sea slugs, Bathydevius uses a cavernous hood, resembling a "Venus flytrap plant," to trap small crustaceans.

In an impressive display of adaptation, the slug also employs a bioluminescent defense, producing a "steadily glowing finger-like projection from the tail" to distract would-be predators, according to the MBARI.

"Everyone in the control room let out a loud ‘Oooooh!’ at the same time. We were all enchanted by the sight," said MBARI Senior Scientist Steven Haddock, who added that only recent advancements in camera technology made it possible to capture this spectacle.

With its translucent, gelatinous hood and tail adorned with finger-like projections, Bathydevius has opened a new chapter in deep-sea research.

"Our discovery is a new piece of the puzzle that can help better understand the largest habitat on Earth," Robison said.

The MBARI team is now eager to explore more about this captivating sea slug, which could potentially reveal other unknown marvels in the ocean's depths.