The deep ocean, particularly in its most mysterious regions like oceanic trenches, has long been a subject of intrigue for scientists. These extreme environments, located up to 11 kilometers (6.8 miles) below the surface, remain largely unexplored due to their pitch-black, freezing conditions and immense pressure—about 1,088 times the normal atmospheric pressure at sea level.

Yet, despite these harsh circumstances, a surprising array of life thrives at these depths. Thanks to advances in research, scientists are beginning to unravel the mysteries of these undersea worlds. A new discovery by a team from the US and Chile is shedding light on one such remarkable creature found in the Atacama Trench off South America's western coast.

Dulcibella camanchaca: The Predator of the Deep

In a groundbreaking study published in Systematics and Biodiversity, the team unveiled Dulcibella camanchaca, a new species of fast-moving, predatory amphipod. Amphipods are shrimp-like crustaceans typically known for scavenging or feeding on detritus in both marine and freshwater environments. However, D. camanchaca breaks the mold by being an active predator found at an astonishing depth of 7,902 meters.

This discovery is particularly significant as D. camanchaca is the first known predatory amphipod to inhabit such extreme depths. Previously, other amphipods in the Atacama Trench were scavengers, making this predator’s existence a remarkable anomaly.

A Glimpse Into the Unknown

The research, led by experts from Chile's University of Concepción and the Woods Hole Oceanographic Institution (WHOI), highlights the sparse knowledge we have about the creatures residing in the deep ocean trenches. The Dulcibella genus is named after Dulcinea del Toboso, a character from the 17th-century Spanish novel Don Quixote, continuing the tradition of naming species after literary figures. The species name "camanchaca," which means "darkness" in indigenous languages of western South America, is fitting given the creature’s habitat in the pitch-black, extreme depths of the trench.

"The name Dulcibella camanchaca reflects its fast-swimming nature and the deep, dark environment it inhabits," said Johanna Weston, co-lead author and hadal ecologist at WHOI. "It signifies the predator's ability to navigate and hunt in an environment where sunlight is completely absent."

Morphology and Behavior: A New Type of Predator

D. camanchaca measures just under 4 centimeters in length, which is more than double the size of its closest relatives, Dorotea and Cleonardo. Unlike many of its fellow amphipods, which are relatively immobile, this species is an agile predator, using specialized appendages called gnathopods to capture prey. It primarily hunts smaller amphipods, which are scarce in these deep-sea environments.

Its ghostly white appearance is typical for creatures living in the darkness of the deep sea, where visibility is virtually nonexistent. This new species offers valuable insights into the adaptability of life in the deepest parts of our planet.

Endemic Life in the Atacama Trench

The Atacama Trench, which extends up to 8 kilometers below the surface, is an area of tectonic activity where one plate slowly slides beneath another. The trench is part of a series of isolated, deep-sea environments known as the hadal zone. These trenches are not only physically separated from one another, but they also harbor unique, often endemic species that are found nowhere else on Earth.

The discovery of Dulcibella camanchaca emphasizes the Atacama Trench as an important hotspot for endemic species. "Most excitingly, the DNA and morphology data pointed to this species being a new genus, too," said Weston, "highlighting the Atacama Trench as a rich source of unique biodiversity."

Exploration and Future Discoveries

This breakthrough came during a 2023 research expedition as part of Chile's new Integrated Deep-Ocean Observing System. The team used specialized lander vehicles to collect samples from the hadal zone, providing a rare glimpse into this harsh environment. With continued exploration, researchers expect to uncover even more species that thrive in the trench’s extreme conditions.
"The importance of deep-ocean exploration, especially in Chile's waters, cannot be overstated," said Carolina González, co-lead author and oceanographer from the University of Concepción. 
As scientists continue to explore these extreme habitats, they not only deepen our understanding of Earth’s marine life but also gather valuable information that could help in the search for extraterrestrial life, particularly on moons like Europa and Enceladus, where environments could resemble Earth's deep-sea trenches.