The deepest part of the ocean is known as the hadal zone, where there is total darkness and extreme pressure. These mysterious regions are between 6,000 and 11,000 meters (3.7 to 6.8 miles) under the ocean's surface, and are mostly made up of deep trenches. The deepest part of the ocean that we know of is called the Mariana Trench, and it is probably the best known part of the hadal zone. Many parts of the hadal seafloor are still being discovered.
Once thought to be mostly devoid of life, the hadal zone is now known to host a diverse array of organisms. But there is still a lot about it we do not know, and it is a difficult place to explore. In 2014, an unmanned submersible was lost forever at a depth of around 10,000 meters in the Kermadec Trench, which is north of New Zealand. A newly designed type of vehicle is expected to reveal a lot more about hadal zones around the world, according to NOAA.
Scientists have now discovered a crustacean species called Dulcibella camanchaca, which they report is the first, active, amphipod crustacean predator to be found at such extreme depths. While it's only about 4 centimeters (1.57 inches) long, it is still considered to be a large organism for its area. It uses special appendages to capture smaller crustaceans in the local environment. It lives in the Atacama trench, which sits along the eastern part of the South Pacific, at depth of 8,000 meters or more. The findings have been reported in Systematics and Biodiversity.
“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,” said co-corresponding study author Dr. Johanna Weston of the Woods Hole Oceanographic Institution (WHOI). “Most excitingly, the DNA and morphology data pointed to this species being a new genus too, emphasizing the Atacama Trench as an endemic hotspot."
The work was made possible by the 2023 Integrated Deep-Ocean Observing System (IDOOS) Expedition, which was conducted on the R/V Abate Molina, and led by scientists from the Instituto Milenio de Oceanografía (IMO), a part of the Universidad de Concepción in Chile.
The researchers recovered four individual Dulcibella camanchaca specimens from a depth of 7,902 meters (4.91 miles) with a lander vehicle that can carry stuff like baited traps to and from the seafloor. The animals were then frozen for a detailed morphological and genetic analysis that was performed 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 co-first study author Dr. Carolina González of the IMO. “More discoveries are expected as we continue to study the Atacama Trench.”
Sources: Woods Hole Oceanographic Institution, Systematics and Biodiversity
