Fortaleza, Brazil – An international team of midwater specialists aboard the research vessel Falkor (too) has identified more than two dozen new marine species during an expedition in international waters off Brazil in the tropical South Atlantic Ocean.

The discoveries were made using advanced imaging systems and genetic analysis to study the ocean’s midwater zone, the layer between sunlit waters and the seafloor, described as Earth’s largest and least explored habitable ecosystem.

Researchers were able to confirm new species within days rather than decades, a process that normally takes far longer.

Among the findings were an amphipod related to crabs and lobsters, a fast-moving gossamer worm, nine jellyfish, seven siphonophores, seven comb jellies, four larvaceans that live in mucus structures, and two giant rhizarians visible without a microscope.

The team also observed unexpected biodiversity, including glass squid and a pelagic octopus feeding on a bright red jellyfish.

Scientists said the midwater remains extremely difficult to explore due to its scale and inaccessibility.

To document the discoveries, the expedition used imaging systems including DeepPIV and EyeRIS, attached to a remotely operated vehicle, which use laser-based scanning to produce 3D images of marine organisms.

A shadowgraph camera was also used to capture fine structural details not visible in 3D scans, allowing scientists to study animal shapes and internal structures without collecting specimens.

Additional tools included a virtual reality chamber designed to simulate natural conditions and a gravity machine used to study microbes under controlled hydrodynamic conditions.

A specialized open-source confocal microscope was also deployed, enabling scientists to capture 3D images of living internal cellular structures in deep-sea organisms for the first time at sea. One organism studied was a large single-celled protist, allowing researchers to observe how its cellular structure interacted with its glass skeleton.

Researchers also sequenced genomes onboard the vessel, helping rapidly identify new species during the expedition.

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