Filmed at 3,000 Meters Deep in Total Darkness, These Ghost Fish Reveal a Pacific We Thought We Knew Well

More than 3,000 meters below the surface of the Pacific Ocean, American researchers have formally described three new species of fish. These gelatinous creatures, filmed as early as 2019 by remotely operated vehicles, thereby confirm an abyssal biodiversity that remains largely little understood by the global scientific community.

Filmed in 2019, Named in 2025: The Long Journey to Identify Three Deep-Sea Ghost Fish

In 2019, the MBARI submersible Doc Ricketts encounters a small pink, bumpy snailfish on the floor of the Monterey Canyon. It is cruising at a depth of 3,268 meters, offshore from California. At that moment, there was no sign that this creature belonged to a species unknown to science.

It took years of genetic analyses, micro-CT scans and meticulous morphological measurements to resolve the question. In August 2025, the journal Ichthyology and Herpetology published the results. This collaborative publication brings together researchers from SUNY Geneseo, the University of Montana and the University of Hawai‘i.

A Trio Like No Other: Pink, Black, Slender—Each Harboring a Vital Deep-Sea Adaptation

The first, Careproctus colliculi, nicknamed the bumpy snailfish, measures 9.2 centimeters long. Its pink, loose skin, its large globular eyes and its 22 fin rays lend it a near-smiling appearance. The biologist Mackenzie Gerringer, who leads the project, describes it as “adorable.”

The second, Careproctus yanceyi, wears an entirely black suit. Its horizontal mouth and elongated body render it a discreet creature, perfectly suited to the cold currents of the deep. The third, Paraliparis em, is even more intriguing: its slender, flattened body lacking a ventral disc deviates from the typical Liparidae blueprint.

Scientists collected these three species during the same 2019 expedition, two of them with the crewed submersible Alvin on the Station M site, at a depth of 4,000 meters. Their coexistence in a zone that has been studied for more than thirty years surprised the researchers themselves.

Station M, one of the most monitored seafloor habitats in the world, still hides unknown species

Station M is a unique abyssal observatory. Instruments there have been collecting data for more than three decades. Yet, in a single dive, researchers identified two entirely new species within the ecosystems of the ocean floor.

For biologist Gerringer, this result perfectly illustrates the current limits of our knowledge. Indeed, only about 5% of the seafloor has undergone precise cartography, according to scientific estimates. The abysses constitute the largest habitat on the planet, and yet remain a largely unexplored territory.

These three gelatinous fishes withstand pressures 800 times greater than atmospheric pressure

Their gelatinous bodies, free of scales and skeletons, show no sign of evolutionary shortcoming. On the contrary, they embody a remarkable adaptation. These structures help the snailfishes to up to 800 times higher than those at the surface, in near-freezing temperatures around 2 °C.

Their well-developed pectoral fins serve not only to propel them. In the total darkness of the abyss, they also function as sensory organs: some fishes perceive their environment by “tasting” the water, compensating for the complete absence of sunlight.

Yet these discoveries raise an urgent question. The active mining of the deep seafloor threatens ecosystems that remain largely unknown. Discovering three new species within a well-documented zone highlights how protecting the abyss has become an essential scientific and environmental priority.