During a 2023 expedition, scientists from the Woods Hole Oceanographic Institution (WHOI) and the Millennium Institute of Oceanography (IMO) aboard the R/V Abate Molina discovered a ghostly white, unusually large predatory amphipod named Dulcibella camanchaca thriving in the Atacama Trench, nearly five miles below the ocean’s surface, according to Live Science. The Atacama Trench, located about 160 kilometers off the coasts of Peru and Chile, is one of Earth's deepest oceanic features, plunging to depths exceeding 26,000 feet (8,065 meters) and stretching approximately 3,666 miles (5,900 kilometers) in length, as reported by The Debrief.
To explore these extreme depths, scientists deployed a special lander vehicle equipped with baited traps to collect specimens of oceanic fauna. During the IDOOS Expedition, experts retrieved four individuals of the large predatory amphipod from a depth of 7,902 meters, according to Science Times. The specimens were frozen and analyzed morphologically and genetically at the Instituto Milenio de Oceanografía (IMO) in Chile. The DNA analysis revealed that this species is new and belongs to an unknown genus, as reported by Science Times.
"This study's collaborative effort and integrative approach confirmed Dulcibella camanchaca as a new species and highlights ongoing biodiversity discoveries in the Atacama Trench," said Dr. Carolina González, a co-lead author from IMO who was responsible for sample collection and DNA analysis. The formal name of the newly discovered species is derived from the term for "darkness" in the languages of the Andes peoples, signifying the deep, dark ocean from where it preys.
"With baited traps, it is essential to remember that we are fishing. And with fishing, there is a lot of skill, but also a lot of luck," said lead author Johanna Weston of the Woods Hole Oceanographic Institution, according to IFLScience. "That is the exciting part of deep-ocean ecology. There is always something new to learn and discover, and we now have one more piece to the puzzle of the Atacama Trench ecosystem."
González described Dulcibella camanchaca as having a slender and agile body that likely allows it to move easily along the seafloor. Its front legs are large and strong, resembling pincers, which are probably ideal for catching and holding prey. Additionally, it has robust teeth in its jaws for cutting and crushing food, as well as legs likely adapted for moving across different types of substrates. "This amphipod is quite large for its type (almost 4 cm [1.6 inches] long), which likely helps it hunt smaller prey. Even though it lacks eyes, it can probably rely on other senses to detect food in the pitch darkness of the ocean floor," she said.
The Dulcibella camanchaca is the first known active large predator of its kind in one of the deepest oceanic zones. Predation is relatively rare in the hadal zone, with most organisms scavenging on organic matter drifting from upper layers of the ocean or relying on chemosynthetic bacteria for nutrients, according to Newsweek. Dulcibella camanchaca, stands out for its specialized hunting abilities, actively preying on smaller crustaceans and invertebrates in an environment where food is scarce.
Hadal zones occupy only 0.25% of the ocean floor but account for the deepest 45% of the ocean, making them the deepest known and least accessible habitats, home to some of the most unusual creatures on the planet. Named after the Greek god of the underworld, Hades, the hadal zone includes deep-sea trenches and troughs. Life in these depths includes unique species like amphipods, sea cucumbers, and xenophyophores, which have evolved adaptations such as soft, compressible bodies to withstand immense pressures, according to Newsweek.
This article was written in collaboration with generative AI company Alchemiq