An expedition in the South Atlantic Ocean has uncovered 31 previously undescribed species living in the mysterious midwater zone off the coast of Brazil. The mission also produced a scientific first at sea, allowing researchers to capture 3D images of the living cellular structure of a single-celled organism.
The discoveries were made during a voyage aboard the Schmidt Ocean Institute research vessel Falkor (too). Using a combination of advanced imaging systems and genome sequencing, scientists were able to identify and document a wide range of species that rarely make it into the spotlight.
From Glowing Jellies To Giant Single-celled Organisms
The expedition revealed a striking collection of new species, many of which seem more at home in science fiction than in Earth’s oceans. Among the newly identified species were delicate Tomopteris worms and translucent comb jellies that move through the water using shimmering, finger-like structures. Researchers also found giant rhizarians, single-celled organisms that grow large enough to be seen with the naked eye.
According to a press release shared by the Schmidt Ocean Institute, the expedition team, the midwater zone is home to an astonishing variety of survival strategies. One example is the larvacean, a tadpole-like creature that builds a large mucus “house” around itself. This structure acts as a filter, capturing tiny food particles drifting through the water.
Scientists also encountered siphonophores, among the ocean’s strangest species. Rather than being a single animal, they are colonies made up of specialized clones, called zooids, that function together as one organism.
“The largest habitat on Earth, the midwater, is filled with incredible animals we are only just starting to understand,” saidKaren Osborn, chief scientist of the expedition and a research zoologist at the Smithsonian National Museum of Natural History.
A New Way to Study Fragile Marine Life
One of the biggest challenges facing deep-sea researchers is that many midwater animals are extremely delicate. Theirsoft, gelatinous bodies can be damaged or distorted when they are collected using traditional methods.
To avoid that problem, the team relied on several imaging technologies mounted on the remotely operated vehicle SuBastian. Based on the information released during the expedition, two systems developed by the Monterey Bay Aquarium Research Institute (MBARI) — DeepPIVand EyeRIS; used laser scans to create detailed 3D images of animals in their natural environment.
A third tool, a shadowgraph camera developed by the Japan Agency for Marine-Earth Science and Technology, captured high-contrast silhouettes that revealed small anatomical features not always visible through laser imaging. The approach allowed scientists to examine many species without removing them from the water, preserving both their appearance and their natural behavior.
First-Ever View Inside a Living Sea Microbe
The expedition was not only about finding new species. It also showcased a series of technologies designed to transform the way marine life is studied. Using the Squid microscope developed at Stanford University, researchers achieved what they described as a first at sea: observing the living cellular structure and glass skeleton of a protist, a type of single-celled organism.
The team also explored animal behavior through a virtual reality application created at the University of Western Australia. Another device, described as a hydrodynamic“treadmill,” simulated an endless water column inside a circular chamber, allowing scientists to observe microbes with minimal disturbance.
“It’s an incredible honor to not only view and experience this rare and inspiring midwater life, but also to be able to work towards describing and sharing that life broadly through the use of novel, non-invasive technologies,” said Kakani Katija, a bioengineer at MBARI.
