During a scientific expedition conducted in the South Atlantic, researchers identified 31 species considered new to science in international waters off the coast of Brazil. The discoveries ranged from jellyfish to organisms such as the silk worm.
The mission, named Designing the Future 3, took place between April 15 and 30, 2026, aboard the vessel Falkor. The expedition was led by zoologist Karen Osborn, affiliated with the Smithsonian National Museum of Natural History in the United States.
Karen Osborn commented in a statement issued by the Schmidt Ocean Institute that the midwater zone, considered the planet's largest habitat, is teeming with remarkable living beings that are still being understood by science.
The studied region, known as the midwater, corresponds to the vast area of the oceanic water column situated between the sunlit surface waters and the seabed. Despite its immense size and ecological relevance, only a small fraction of this ecosystem has been investigated. The Smithsonian reports that the midwater spans approximately one billion cubic kilometers and performs crucial functions, such as the global carbon cycle.
Catalog of little-known creatures
Among the 31 new species cataloged are nine types of jellyfish, seven siphonophores, seven ctenophores, four larvaceans, two giant radiolarians, one amphipod, and one worm belonging to the genus Tomopteris.
Siphonophores, relatives of corals and jellyfish, have a peculiarity: each visible unit is actually a colony composed of specialized parts that act together. One highlight was a new species of the genus Tomopteris, popularly referred to as gossamer worms.
Ctenophores move using rows of cilia that create a shimmering effect when interacting with light, while larvaceans resemble tadpoles and inhabit mucous structures used, among other purposes, to filter aquatic particles. Additionally, giant radiolarians were found, single-celled organisms that can be observed without instrumental aid.
One of the central elements of the expedition was a new specimen of Tomopteris, or silk worm. The Schmidt Ocean Institute classified this animal as a new species of the genus, noting that its movement was faster than expected given its body morphology.
The swimming ability of these animals had already attracted the attention of the scientific community. A jellyfish expert, Dr. Dhugal Lindsay (JAMSTEC), mentioned the scanning of a new siphonophore species.
A previous study, published in 2021 in the journal Integrative and Comparative Biology and involving Karen Osborn, demonstrated that Tomopteris use two propulsion methods: body undulations and coordinated movements of appendages called parapodia. Researchers observed that these appendages actively generate thrust, and the undulating movement of the body assists in this propulsion process.
These Tomopteris live entirely in the water column and have an extremely fragile body, composed mainly of fluid, enveloped by a thin layer of gel and muscle. The way they swim not only contributes to understanding their survival in the ocean but also interests scientists in other fields. The researchers noted in the study that tomopterids represent a unique case of combining various propulsion mechanisms, suggesting that their biomechanics may have applications in fields such as robotics and flexible material engineering.
How to determine if a species is new?
To classify an organism found in the depths as an unknown species, its unusual appearance is not enough; morphological comparisons and, whenever possible, genetic data analysis with already documented organisms are necessary.
This procedure is particularly challenging for gelatinous animals, as many have transparent and very fragile bodies, which can suffer deformation or damage during collection and preservation.
A 2024 study, published in the journal Science Advances, illustrated how new technologies help overcome part of this difficulty. This work integrated three-dimensional imaging, robotics, tissue preservation, and genetic sequencing to gather information about living beings in their natural environment.
Among the tools used were DeepPIV, which uses lasers to generate three-dimensional data, and EyeRIS, an imaging system capable of capturing morphological details of the animals. These devices were installed on the ROV SuBastian, a remotely operated submersible by the Schmidt Ocean Institute.
In the 2024 study, scientists obtained size data for 61 animals with EyeRIS and scanned 49 individuals with DeepPIV, including siphonophores and a Tomopteris. In the 2026 expedition, this technological apparatus was expanded. Scientists used advanced imaging systems to observe the animals and set up a genetics laboratory aboard the Falkor, allowing for the comparison of characteristics and genetic sequences during the voyage. According to the involved institutions, the combination of technology and taxonomic knowledge enabled the confirmation of the 31 species as new in just a few days, a process that normally takes years.
An almost invisible world
The new species were not the only surprises recorded. Researchers also documented a young glass squid and a pelagic octopus (Haliphron atlanticus) consuming a bright red jellyfish. The team noted a diversity and abundance of midwater organisms exceeding expectations.
The expedition also included Brazilian participation. Silvina Botta, from the Federal University of Rio Grande (FURG), was among the researchers aboard, working with samples intended for stable isotope analysis to study carbon movement in the ocean.
The discoveries contribute to revealing the biodiversity of a vast environment that remains largely unknown. The Smithsonian emphasizes that midwater communities play a significant role in global biogeochemical processes, such as carbon retention and release. Despite finding dozens of species in just two weeks, Karen Osborn stated that the expedition generated, above all, new questions.