What New Species Were Discovered in the Ocean's Midwater Zone Off Brazil?

31 New Species Found in Brazil’s Deep Midwater Zone

Scientists aboard the research vessel Falkor (too) discovered 31 species never previously documented, found in the midwater zone off the coast of Brazil — including jellyfish, comb jellies, siphonophores, larvaceans, and a gossamer worm.

What Is the Midwater Zone?

The midwater zone begins roughly 660 feet below the ocean’s surface, where sunlight completely disappears. Despite being the largest living space on Earth by volume, it remains one of the least explored environments ever studied. Scientists estimate that more unknown life exists here than anywhere else on the planet. Most of what lives in this vast, lightless column has never been catalogued — and may not be for decades.

The Expedition: RV Falkor (too) and ROV SuBastian

The Schmidt Ocean Institute operates the Falkor (too), a state-of-the-art research vessel equipped with ROV SuBastian, a remotely operated vehicle rated to depths of nearly 15,000 feet. During a single expedition off Brazil’s coast, an international scientific team deployed SuBastian into the midwater darkness and returned with documented evidence of 31 species that had never appeared in the scientific record. The finds spanned multiple animal groups and ranged from nearly invisible filter-feeders to colonial organisms of extraordinary length.

The Most Remarkable Finds

Siphonophores: The Longest Animals on Earth

Among the new species, siphonophores drew immediate attention. These colonial organisms can stretch up to 130 feet in length, placing them among the longest animals known to science. What makes siphonophores genuinely strange is that they are not a single creature. Each siphonophore is a colony of thousands of individual organisms — called zooids — that function as one coordinated body. Different zooids handle different tasks: locomotion, feeding, reproduction. They are simultaneously one animal and many.

Larvaceans: Small Animals, Global Consequences

Larvaceans look almost impossibly small — often no bigger than a thumbnail. But their impact on the planet’s climate is measurable. These tiny creatures construct elaborate mucus structures, sometimes nearly three feet wide, which act as filtering houses to capture ocean particles. When the structure becomes clogged, the larvacean abandons it. The discarded mucus house — packed with organic carbon — sinks to the seafloor. This process, repeated by countless larvaceans across the world’s oceans, transports significant quantities of carbon from the surface waters down into deep storage. Larvaceans are a meaningful part of the biological carbon pump that regulates Earth’s atmosphere.

Comb Jellies and a Gossamer Worm

The expedition also documented new species of comb jellies — bioluminescent predators that use rows of fused cilia to move through the water — as well as a gossamer worm, a delicate, translucent polychaete adapted to life in the midwater column. Each find adds a new data point to a picture of ocean life that science is only beginning to assemble.

Why This Discovery Matters

Thirty-one new species from a single expedition is not a routine result. It reflects just how little human science has penetrated the midwater zone, and how much biological diversity remains uncharted in Earth’s largest habitat. These animals are not curiosities — they are functioning parts of ocean ecosystems that regulate carbon, feed larger predators, and sustain the chemistry of the seas. Every undocumented species represents a gap in our ability to understand and protect the systems that make the planet habitable. The Falkor (too) expedition is a reminder that the most alien environments on Earth are not on distant planets — they are directly beneath the ocean’s surface.