A guitar-shaped shark is among 866 new species found on deep-ocean dives

An international mission to speed up the cataloging of ocean life has announced a wave of discoveries drawn from waters ranging from sunlit shallows to the crushing dark thousands of meters down. Its most eye-catching find is a flattened, elongated relative of sharks and rays whose body outline resembles the silhouette of a guitar.

866 new species in one announcement

The Ocean Census, a global alliance formed to accelerate the discovery of marine life, detailed 866 species new to science in a single update. The organizers described it as a major early milestone for a project that aims to document a far larger share of the ocean’s undiscovered biodiversity in the years ahead.

The animals were collected using divers, crewed submersibles, and remotely operated vehicles, with specimens recovered from depths spanning roughly one meter to nearly 5,000 meters. That range reflects the mission’s strategy of sampling across the full vertical sweep of the sea rather than concentrating on any single habitat.

Spreading effort across such a wide band of depths is a deliberate choice. Life near the surface has been studied for centuries, but the numbers of species and individuals change dramatically with depth, and the animals of the mid-water and seafloor remain comparatively unknown. By reaching from the shallows to the deep on the same program, the mission aimed to capture a fuller cross-section of ocean life than any single dive or shallow survey could provide.

The guitar shark that stole the spotlight

The standout creature was a guitar shark, a member of a group more precisely known as guitarfish that sits between true sharks and rays in body plan. With a flattened front end and a slender, shark-like tail, the animal earns its name from a profile that curves like the instrument.

The specimen was identified at around 200 meters of depth in waters off the coasts of Mozambique and Tanzania by a shark specialist known for tracking down rarely seen species. An overview of that discovery and the wider mission appears in a report on the ambitious effort to document marine life.

A group already under pressure

The find is notable beyond its novelty because guitarfish as a whole are among the more threatened groups of cartilaginous fishes. The newly recognized animal was described as only the 38th known species of guitar shark, and a large majority of those species are considered at risk, largely because their shallow, coastal habitats overlap heavily with fishing activity.

Documenting a new member of such a vulnerable group carries added weight, since a species cannot be assessed or protected until it has been formally named and its range understood.

Beyond the shark: mollusks, corals, and more

The guitar shark shared the announcement with a broad mix of other organisms, including a deep-sea mollusk and a soft coral reported as a first record for the waters around the Maldives. Together the finds spanned multiple branches of the tree of marine life, from invertebrates to fish, reflecting the mission’s aim of surveying whole ecosystems rather than charismatic animals alone.

The alliance behind the work has framed the 866 species as an opening figure. Its stated ambition is to help uncover a large portion of the tens of thousands of marine species that scientists believe remain undescribed, as summarized in the project’s own account of the discovery of more than 800 new species.

Why the deep sea keeps surprising researchers

The sheer depth range of the discoveries helps explain why the ocean remains so poorly cataloged. Sampling far below the surface demands specialized vehicles and long, expensive expeditions, so vast stretches of the seafloor have simply never been examined at the resolution needed to spot small or well-camouflaged animals.

Each descent tends to return with organisms that no reference collection contains, which is why a coordinated, repeatable program can add hundreds of species at once. The bottleneck has historically been not the ocean’s diversity but the slow, specialist-heavy process of describing what gets hauled up.

An early marker in a long project

Taken together, the 866 species represent a proof of concept for treating discovery as an organized pipeline rather than a scattering of isolated finds. By pairing expeditions with networks of taxonomists, the mission has compressed a process that often takes many years per species into something far faster.

The announcement also carries a note of urgency. Some of the newly recognized animals belong to groups already under strain from fishing, habitat loss, and warming seas, which means a number of them may be described and identified as vulnerable almost simultaneously. Naming a species is often the first step toward protecting it, and in the case of the guitar shark that step arrives for an animal whose relatives are among the most imperiled fishes in the sea.

The guitar shark, with its instantly recognizable shape and its place in a threatened family, serves as a fitting emblem for the effort: a striking reminder that even large, distinctive animals can still be waiting, unnamed, in waters that research vessels have only begun to explore.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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