A siphonophore — a colonial marine invertebrate related to the venomous Portuguese man-of-war — is scanned using Deep Particle Image Velocimetry (DeepPIV) at a depth of 350 meters.
In just 15 days, researchers aboard the ship Falkor (too) identified 31 species considered new to science in international waters off Brazil. The mission, called Designing the Future 3, took place between April 15 and 30, 2026 and was led by zoologist Karen Osborn, from the Smithsonian's National Museum of Natural History, in the United States.
“Earth’s largest habitat, midwater, is full of incredible animals that we are only beginning to understand,” said Karen Osborn, in a statement released by the Schmidt Ocean Institute.
The region studied is known as mid-water: the gigantic portion of the oceanic column located between the surface waters illuminated by the Sun and the seabed. Despite its size and ecological importance, only a small fraction of this environment has been explored by scientists. According to the Smithsonian, the mid-water area occupies around 1 billion cubic kilometers and participates in processes such as the global carbon cycle.
Among the 31 species identified are nine jellyfish, seven siphonophores, seven ctenophores, four larvaceans, two giant rhizarians, one amphipod and a worm of the genus Tomopteris.
Siphonophores are related to jellyfish and corals, but they have a curious characteristic: each apparent individual is, in fact, a colony made up of specialized units that work together.
Ctenophores, in turn, move with rows of cilia that produce a sparkling effect when interacting with light. Larvaceans, on the other hand, have an appearance that resembles tadpoles and live in mucus structures used, among other functions, to filter particles from the water.
There are also giant rhizarios. Although they can be observed with the naked eye, they are organisms made up of a single cell.
One of the protagonists of the expedition was a new representative of Tomopteris, a group known in English as gossamer worms, an expression that can be translated as “silk thread worms”. The Schmidt Ocean Institute identifies the animal recorded during the mission as a new species of the genus and highlights that it moves faster than scientists would expect considering the shape of its body.
The swimming ability of these animals had already attracted the attention of science. A study published in 2021 in the journal Integrative and Comparative Biology, with the participation of Karen Osborn herself, showed that Tomopteris combine two propulsion mechanisms: body undulations and coordinated movements of appendages called parapodia. The researchers observed that these appendages actively generate thrust and that the wave-like movement of the body helps to enhance propulsion.
Tomopteris spend their entire lives in the water column and have an extremely delicate body, made up largely of fluid, surrounded by a thin body wall with gel and muscles.
In addition to helping to understand how these animals survive in the ocean, the way they swim draws the attention of researchers in other areas. “Tomopterids are a unique example of a combination of different propulsion mechanisms,” the researchers note in the study. According to the authors, the biomechanics of these animals may have applications in areas such as flexible materials engineering and robotics.
How do you know that a species is new? Finding a strange animal in the depths is not enough to conclude that it is an unknown species. It is necessary to compare morphological characteristics and, when possible, genetic information with already known organisms.
This process is particularly complicated for gelatinous animals. Many have transparent and extremely fragile bodies, which can be deformed or destroyed during capture and preservation.
A study published in 2024 in the journal Science Advances showed how new technologies can overcome part of this problem. The work brought together three-dimensional imaging, robotics, tissue preservation and genetic sequencing to obtain information about organisms still in their natural environment.
Among the tools are DeepPIV, which uses a laser to produce three-dimensional information, and EyeRIS, an imaging system capable of recording details of animal morphology. The equipment can be installed on the ROV SuBastian, an underwater vehicle operated remotely by the Schmidt Ocean Institute.
In the 2026 expedition, this technological arsenal was expanded. Scientists used advanced imaging systems to observe the animals and set up a genetics laboratory inside Falkor itself (too). This way, they were able to compare characteristics and genetic sequences during the trip. According to the institutions involved, the combination of technology and taxonomic knowledge made it possible to confirm the 31 species as new in a matter of days — a process that traditionally can take years.
The new species were not the only surprises. The researchers also recorded a juvenile glass squid, as well as a pelagic octopus (Haliphron atlanticus) feeding on an intense red jellyfish. The team found a greater diversity and abundance of midwater organisms than they expected.
The expedition also included Brazilian participation. Among the researchers on board was Silvina Botta, from the Federal University of Rio Grande (FURG), who worked with samples intended for stable isotope analysis to investigate the movement of carbon through the ocean.
The discoveries help to reveal the biodiversity of a gigantic environment that remains largely unknown. The Smithsonian highlights that midwater communities play a relevant role in global biogeochemical processes, including carbon retention and release.
Even after finding dozens of species in just two weeks, for Karen Osborn the expedition left mostly new questions. “I continue to be fascinated by the fantastic variety of solutions they have developed to survive in this formidable environment, and this leads me to continue asking questions about our ocean,” said the researcher.
