57 new deep-sea species discovered in Argentina’s Mar del Plata Canyon, including ‘Loki’ sea cucumber

Photo credit: ROV SuBastian / Schmidt Ocean Institute A deep-sea expedition off the coast of Argentina has yielded a remarkable scientific harvest. After analysing samples collected in the Mar del Plata Submarine Canyon, an international team confirmed the discovery of 57 new marine species and five new genera in just two weeks of intensive work. Among the most eye-catching finds is a translucent sea cucumber with horn-like appendages that researchers nicknamed Loki, a nod to the horned Norse god, according to reports from Ocean Census and Oceanographic Magazine.A canyon that hides a world of lifeThe Mar del Plata Submarine Canyon is a vast underwater valley that cuts into the continental slope off Argentina’s Atlantic coast. Such canyons act as conduits for nutrients and organic material, creating rich habitats for diverse deep-sea communities. During the Talud Continental IV campaign in August 2025, the research vessel R/V Falkor (too) used a remotely operated vehicle to descend to nearly 3,900 metres and collect biological samples from the canyon walls and floor.The specimens were later brought to a Species Discovery Workshop in San Carlos de Bariloche, where about twenty taxono...