Discovery of New Deep-Sea Species in the Southern Ocean

In 2025, scientists from The Nippon Foundation-Nekton Ocean Census and the Schmidt Ocean Institute conducted research expeditions in the Southern Ocean, uncovering 30 previously unknown deep-sea species. The discoveries were made during two research cruises that explored remote areas, including volcanic calderas and the South Sandwich Trench, using advanced technology such as the ROV SuBastian. The findings were officially verified at the Southern Ocean Species Discovery Workshop held at Universidad de Magallanes in Punta Arenas, Chile.

Carnivorous “death-ball” sponge among new deep-sea speciesDaily Beast‘Death Ball’ Sponge and Glowing Worms Among Creatures Discovered in Southern Ocean

Among the newly identified species is a carnivorous sponge, Chondrocladia sp. nov., nicknamed the "death ball." This spherical sponge is unique for its tiny hooks that trap prey, contrasting with the typical filter-feeding behavior of most sponges. Other notable discoveries include iridescent scale worms (Eulagisca sp. nov.), new species of sea stars from the families Brisingidae, Benthopectinidae, and Paxillosidae, as well as various crustaceans, gastropods, and bivalves adapted to extreme environments.

The Guardian

The research team collected nearly 2,000 specimens across 14 animal groups and documented their findings through hours of high-definition video and thousands of images. The expeditions also yielded significant ecological insights, including the first confirmed footage of a juvenile colossal squid and the discovery of new hydrothermal vents and coral gardens.

Carnivorous “Death-Ball” Sponge Among 30 New Deep-Sea Species From The Southern Ocean

Dr. Michelle Taylor, head of science at The Nippon Foundation-Nekton Ocean Census, emphasized the significance of these discoveries, stating, “The Southern Ocean remains profoundly undersampled. To date, we have only assessed under 30% of the samples collected from this expedition, so confirming 30 new species already shows how much biodiversity is still undocumented.” The findings contribute to a broader understanding of marine biodiversity and underscore the necessity of continued exploration in under-researched areas.

Daily Beast

While the discoveries are celebrated, some critics argue that the focus on new species may overshadow the urgent need for conservation efforts in these fragile ecosystems. The accelerated pace of species discovery, as noted by Mr. Mitsuyuki Unno, Executive Director of The Nippon Foundation, is essential for public good, but it raises questions about the long-term impacts of human activity on these remote habitats.

Carnivorous “Death-Ball” Sponge Among 30 New Deep-Sea Species From The Southern Ocean

• “Accelerating species discovery is not a scientific luxury, it is essential for public good,” — Mitsuyuki Unno, Executive Director, The Nippon Foundation

Carnivorous “Death-Ball” Sponge Among 30 New Deep-Sea Species From The Southern Ocean

• “Each confirmed species is a building block for conservation, biodiversity studies, and untold future scientific endeavors.” — Michelle Taylor, Head of Science, The Nippon Foundation-Nekton Ocean Census

Carnivorous “Death-Ball” Sponge Among 30 New Deep-Sea Species From The Southern Ocean

The Ocean Census program plans to continue its efforts in the Southern Ocean, with additional assessments of potential new species, including black corals and a possible new sea pen genus. The ongoing research aims to enhance understanding of deep-sea ecosystems and inform conservation strategies in the face of climate change and human impact.

Carnivorous “Death-Ball” Sponge Among 30 New Deep-Sea Species From The Southern Ocean