Following a deep-sea expedition into Argentina’s submarine canyons, and the subsequent international Species Discovery Workshop, 57 new marine species and five genera have been discovered by scientists from the Ocean Census Network.
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One of the most unusual findings among the new species is ‘Loki the Sea Cucumber’ (Peniagone sp.), named for its horned appendages resembling the legendary Norse god.
In total, the researchers identified 20 new species of copepods (small crustaceans), 22 echinoderms (sea cucumbers and crinoids), 14 cnidarians (octocorals, sea pens and stony corals) and one scaphopod mollusc, with five new scientific genera spanning corals, sea cucumbers and crustaceans.
These discoveries are the result of the Schmidt Ocean Institute Underwater Oases of the Mar del Plata Canyon expedition, which took place between July and August 2025 aboard the research vessel Falkor (too).
Explorations focused on the Brazil-Malvinas Confluence off the coast of Argentina and Uruguay, where warm subtropical currents collide with cold, nutrient-rich sub-Antarctic waters, creating an extraordinary crossroad of biological productivity.
Operating in a submarine canyon nearly twice as deep as the Grand Canyon (exceeding 3,500 metres), the team used the remotely operated vehicle (ROV) SuBastian to broadcast live video feeds directly to the public.
Over four million viewers tuned in to witness the sprawling deep-sea coral reefs and fields of mushroom coral. One highlight was observing a bright orange sea star with a strong resemblance to the cartoon character Patrick Star – although it wasn’t determined to be a new species.
Identifying new species
The Species Discovery Workshop, held in July 2026 and led by the Nippon Foundation-Nekton Ocean Census in partnership with the Schmidt Ocean Institute, marks the one-year anniversary of the expedition.
The workshop brought together 20 taxonomists and early-career researchers from across Latin America and Europe, providing hands-on training and allowing knowledge exchange between local and international taxonomic experts.
The team utilised integrated taxonomy techniques to rapidly identify specimens, logging discoveries directly onto Ocean Census NOVA: the world’s first open-access data platform for newly discovered marine species.
“International cooperation in taxonomy is critical, especially in groups with few active specialists,” says Daniel Lauretta, the principal investigator of the expedition. “The species discovery workshop accelerated species identification, the recognition of species new to science, and increased capacity building for local early-career taxonomists working on deep-sea fauna.”
Beyond species counts, the workshop was a major investment in Argentine scientific capacity and regional biodiversity research. The scientists examined not only physical specimens but also historical samples from the National Scientific and Technical Research Council’s (CONICET) Talud Continental I-III expeditions conducted in 2012 and 2013.
All samples will be permanently housed in national institutional collections, including the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” (MACN) in Buenos Aires.
“Discovering 57 new species and five genera in just two weeks demonstrates the speed and power of collaborative taxonomy,” says Michelle Taylor, Ocean Census’ head of science.
“The deep sea holds some of the least understood ecosystems on Earth. By bringing Latin America’s scientific expertise and international experts together, as well as connecting them to the open-access Ocean Census NOVA platform, we are drastically accelerating our understanding of marine biodiversity.”
The discovery journey in the South Atlantic is far from over – a follow-up expedition with Schmidt Ocean Institute is planned for February and March 2027, this time to explore a different submarine canyon with suspected high endemism.
New species highlights
"Loki the Sea Cucumber" (Peniagone sp.)
A standout discovery of the workshop, this striking deep-sea holothurian (sea cucumber) was named "Loki" for its prominent horned appendages, reminiscent of the god in Norse mythology. It represents one of up to 10 new holothurian species uncovered during the Argentina workshop.
Taxonomist: Francisco Alonso Solís-Marín and Mariano Martinez (CONICET)
Copepod (Pseudotachidius sp.)
Found between 1,909 and 2,625 metres deep in Argentina’s Mar del Plata Canyon and Deep Basin, this tiny copepod is part of a group of crustaceans that play a vital role in deep-sea ecosystems. During the workshop, taxonomists examined just 10% of the copepod samples collected — yet every specimen examined proved to be new to science, contributing to the discovery of 20 new species and one new genus.
Taxonomist: Nancy Mercado Salas and Emanuel Pereira
Octocoral (Orstomisis sp.)
A striking, bright red-orange octocoral documented in situ on the soft substrates of the deep ocean floor. Captured at a depth of 1,954 metres, this specimen contributes vital data to our understanding of habitat-forming, deep-sea coral ecosystems in Argentina’s Mar del Plata Canyon.
Taxonomist: Ralf Cordeiro and Daniel Lauretta (CONICET)
Sea pen (Pseudumbellula sp.)
Detailed imagery captures this vibrant sea pen living on the seafloor, as well as its careful collection using the robotic manipulator arm of ROV SuBastian. This colonial coral represents one of 14 new cnidarian species identified during the species discovery workshop.
Taxonomist: Jessica Risaro (CONICET) and Pablo Lopez-Gonzalez
Holothurian (Benthothuria sp.)
An extraordinary photograph of a bright purple holothurian (sea cucumber) resting on the seabed of the Mar del Plata Canyon. This specimen was analysed alongside dozens of other echinoderms by international experts during the species discovery workshop in Buenos Aires.
Taxonomist: Francisco Alonso Solís-Marín and Mariano Martinez (CONICET)
More deep-sea discoveries:
- When an underwater robot was sent to the bottom of a deep-sea canyon, it made an astounding discovery
- Deep-sea submersible films thousands of bizarre red animals 1,500m deep off coast of Argentina
- A deep-sea robot went to one of the darkest places on Earth – what it found was staggering
- Scientists just photographed a place that's never been seen by humans before. What the images reveal is shocking
Top image credit: ROV SuBastian / Schmidt Ocean Institute
