Characterized by darkness and intense pressure, the ocean's hadal zone seems uninhabitable, yet dozens of unique organisms call it home. Each species discovered there adds a crucial piece to the puzzle of how life has evolved and even thrives in one of Earth's most extreme environments.
A new study published in Systematics and Biodiversity highlights one of those species -- the newly named Dulcibella camanchaca. This crustacean is the first large, active predatory amphipod from these extreme depths. The species was discovered by scientists from Woods Hole Oceanographic Institution (WHOI) and Instituto Milenio de Oceanografía (IMO)based at the Universidad de Concepción, Chile.
"Dulcibella camanchaca is a fast-swimming predator that we named after "darkness" in the languages of the peoples from the Andes region to signify the deep, dark ocean from where it predates," explained the study's co-lead author, Dr. Johanna Weston, a hadal ecologist at WHOI.
At nearly 4 centimeters in length, this crustacean uses specialized raptorial appendages to capture and prey upon smaller amphipod species in the Atacama (Peru-Chile) Trench's food-limited realm. The trench stretches along the eastern South Pacific Ocean, plunging to depths exceeding 8,000 meters off the coast of northern Chile, and has long fascinated scientists. Located beneath nutrient-rich and productive surface waters and geographically remote from other hadal environments, the Atacama Trench hosts a distinctive community of native species.
"Most excitingly, the DNA and morphology data pointed to this species being a new genus too, emphasizing the Atacama Trench as an endemic hotspot," continued Weston.
This remarkable finding is part of the 2023Integrated Deep-Ocean Observing System (IDOOS) Expedition aboard the R/V Abate Molina, led by scientists from IMO. Four Dulcibella camanchaca individuals were collected at a depth of 7,902 meters using a lander vehicle, which is an untethered platform used for carrying scientific equipment, including baited traps, to and from the ocean floor. Once safely back on the ship's deck, recovered amphipods were frozen and then underwent detailed morphological and genetic analysis at the Universidad de Concepción.
"This study's collaborative effort and integrative approach confirmed Dulcibella camanchaca as a new species and highlights ongoing biodiversity discoveries in the Atacama Trench. This finding underlines the importance of continued deep-ocean exploration, particularly in Chile's front yard," said Dr. Carolina González, co-lead author from the IMO responsible for sample collection and DNA analysis. "More discoveries are expected as we continue to study the Atacama Trench."
As exploration technology advances, scientists anticipate uncovering more species, each offering insights into the evolutionary pressures and adaptations unique to the deep ocean. The results of this study will contribute to broader efforts to understand deep-ocean ecosystems and protect them from emerging threats, such as pollution and climate change.