In News:

• In a groundbreaking discovery, researchers have identified a new species of sea slug deep within the ocean’s midnight zone—a place that lies between 3,300 to 13,100 feet (1,000 to 4,000 meters) below the ocean's surface.
• The species, named Bathydeviuscaudactylus, is a glowing, swimming sea slug that exhibits several unique adaptations to survive in the extreme conditions of the deep ocean.

Key Features of BathydeviusCaudactylus

• Glowing Bioluminescence: One of the most striking features of this newly discovered mollusk is its ability to glow with bioluminescence. Bathydevius emits a soft, starry glow, an adaptation seen in only a few deep-sea species. The glowing feature plays a role in distracting predators and even includes the ability to detach glowing projections from its tail as a decoy.
• Unique Body Structure: Unlike most sea slugs that typically live on the seafloor, Bathydevius has evolved to thrive in the open water. It has a gelatinous, paddle-like tail and a large, bowl-shaped hood that covers its internal organs, making it appear somewhat like a “megaphone with a feathered tail.” This structure helps it capture prey, such as mysid shrimp, which it traps using its hood.
• Adaptations for Deep Sea Life: Bathydevius' transparent body, along with its ability to drift with ocean currents and flex its body to move vertically in the water column, allow it to navigate the depths of the midnight zone. Its hermaphroditic nature means it carries both male and female reproductive organs, allowing it to reproduce by attaching to the seafloor and laying eggs when needed.

Discovery and Exploration

• The unusual species was first encountered by researchers from the Monterey Bay Aquarium Research Institute (MBARI) during a deep-sea dive in February 2000 using a remotely operated vehicle (ROV) called Tiburon. Since then, more than 150 sightings have been made of the creature in the waters off the Pacific Coast of North America, ranging from Oregon to Southern California.
• Interestingly, similar creatures have been observed by the National Oceanic and Atmospheric Administration (NOAA) in the Mariana Trench, suggesting that Bathydevius may have a wider range than initially thought. A specimen was eventually collected for further study, revealing its identity as a nudibranch, a type of soft-bodied marine mollusk.

Survival Tactics and Behavior

• Prey Capture: Unlike typical sea slugs that scrape food from the seafloor, Bathydevius uses its large hood to trap crustaceans like mysid shrimp. This allows it to thrive in the open ocean where food can be harder to obtain.
• Defensive Mechanisms: When threatened, Bathydevius can glow with bioluminescence to distract predators. This glow, which creates a starry appearance across its back, has been seen in other deep-sea species but is rare in nudibranchs. Additionally, it can detach part of its tail (a glowing projection) to confuse attackers, similar to how lizards shed their tails as a defense mechanism.
• Reproduction and Movement: As a hermaphrodite, Bathydevius has the ability to self-fertilize or mate with other individuals. During reproduction, it descends to the seafloor and uses its foot to temporarily attach, releasing eggs before returning to its swimming lifestyle. It also relies on its flexible, transparent body to blend in with the surroundings and evade predators.