A translucent sea cucumber with two horn-like appendages just got nicknamed after a Norse trickster god — and it's only one of 57 species nobody had ever seen before a two-week workshop in Argentina.
- 57 new marine species confirmed
- 5 new genera described
- Specimens collected from depths near 3,900 meters
- Workshop turned raw samples into named species in just two weeks
A canyon built to hide biodiversity
The Mar del Plata Submarine Canyon cuts deep into the continental slope off Argentina's Atlantic coast, the kind of underwater valley that funnels nutrients and organic material down from shallower waters and concentrates life along its walls. In August 2025, the research vessel R/V Falkor (too), operated by the Schmidt Ocean Institute, sent a remotely operated vehicle down to nearly 3,900 meters to collect samples from the canyon floor and walls during an expedition called Talud Continental IV.
Those samples didn't sit in a queue for years, which is the usual fate of deep-sea specimens. Instead they went straight to a Species Discovery Workshop in San Carlos de Bariloche, where roughly twenty taxonomists from Latin America and Europe examined them under microscopes side by side, comparing new finds against known species in real time.
From 40 candidates to 57 confirmed species
What started as a preliminary estimate of around 40 new species grew to 57 as specialists worked through the full collection — a tally that includes 20 new species of copepods, 22 new echinoderms such as sea cucumbers and crinoids, 14 new cnidarians including octocorals and sea pens, and one new scaphopod mollusc.
The breakout find is a sea cucumber in the genus Peniagone, informally nicknamed Loki after the horned Norse god, found at a depth of 2,577 meters. Its translucent body and paired horn-like projections made it an instant standout among the collection, though scientifically it's just one data point in an unexpectedly rich inventory.
"The most abundant animals on Earth — copepods, the small crustaceans that form the base of every marine food web — were, in a single deep-sea canyon off Argentina, entirely unknown to science."
Why fast taxonomy changes the conservation math
The project, run jointly by Ocean Census and the Schmidt Ocean Institute with Argentina's CONICET research council, is a test case for a different way of doing deep-sea biology. Traditionally, specimens pulled from ROV dives can wait years for formal description while they move through academic backlogs one paper at a time. Putting twenty specialists in a room with shared equipment and open data compressed that timeline from years to two weeks.
That speed matters beyond scientific bragging rights. Deep-sea canyons like Mar del Plata are increasingly targeted for fishing, cable routes, and mineral exploration, and policymakers can't protect species that haven't been named yet. A 100% novelty rate across the workshop's initial sample set suggests how much of the canyon's biology was previously invisible to the people who might eventually decide its fate.
Researchers expect the final count to climb further as less-studied groups get a closer look, and a follow-up expedition to a different submarine canyon is already planned for early 2027. For a patch of ocean most people will never see, the Mar del Plata Canyon just became one of the better-documented deep-sea ecosystems in the South Atlantic — proof that there's still plenty left to find close to a coastline, not just in the most remote corners of the map.
