Marine Scientists Identify a Record 1,121 New Ocean Species, Including a Deep-Sea Ghost Shark and a Glass-Sponge 'Castle' Off Japan

Level 2 — Elementary

On Tuesday, May 19, 2026, the Nippon Foundation-Nekton Ocean Census announced a record number of new marine discoveries. Researchers from around the world identified 1,121 species new to science in the past year. That is 54 percent more than the year before.

Among the highlights is a strange deep-sea fish called a ghost shark, which is actually a cartilaginous relative of true sharks and rays. The new species was photographed at about 2,700 feet below the surface in Australia's Coral Sea Marine Park.

Japanese researchers found a community of bristle worms living inside the intricate, glass-like skeleton of a deep-sea sponge on a volcanic seamount. The scientists nicknamed the structure a 'glass castle' because the sponge's skeleton is made of pure crystalline silica.

The new species also include corals, crabs, shrimps, sea urchins and anemones. Some were found at depths greater than four miles. The Ocean Census says these animals show how much life remains undescribed, especially deep below the surface.

marine: relating to the sea or ocean

cartilaginous: having a skeleton made of cartilage, like sharks and rays

seamount: an underwater mountain rising from the ocean floor

crystalline: made of crystals; clear and glass-like

silica: a mineral, the main material in sand and glass

anemone: a soft, flower-like sea animal that catches prey with stinging tentacles

undescribed: not yet officially described or named by scientists

highlight: the most interesting or impressive part of something

Level 3 — Intermediate

The Nippon Foundation-Nekton Ocean Census unveiled the headline results of its second full year of operations on Tuesday, May 19, 2026, announcing the discovery of 1,121 species new to science — a 54 percent year-on-year increase and the largest annual yield since the initiative was launched. The findings span tropical reefs, abyssal plains, hydrothermal vents and the seamount chains that run beneath the world's three great oceans.

Among the showcase animals is a previously undescribed ghost shark, a holocephalan cousin of true sharks and rays photographed by remotely operated vehicles at roughly 820 metres in Australia's Coral Sea Marine Park. Holocephalans diverged from elasmobranchs more than 300 million years ago and retain a deeply unusual anatomy: cartilaginous skeletons, fused tooth plates, and oversized eyes adapted to the near-darkness of the bathypelagic zone. The animal's pale skin and unhurried glide earned the 'ghost shark' nickname long before this new species was catalogued.

Japanese marine biologists added a different sort of surprise. On a volcanic seamount in the Pacific, an iridescent glass sponge — its skeleton spun from biomineralised silica spicules — was found to house a community of symbiotic bristle worms in its chambered interior. The team nicknamed the structure a 'glass castle' and is now investigating whether the worms aid the sponge by removing detritus and parasites, much like cleaner fish on a tropical reef.

The 1,121 catalogued species span corals, crustaceans, echinoderms, anemones and dozens of unfamiliar deep-sea fishes. Some were retrieved at depths exceeding six kilometres — pressures that exclude all but the most specialised submersibles. Census director Mitsuyuki Unno told reporters that even with this leap in pace, the team estimates that more than 90 percent of the deep ocean's animal life remains undescribed, a sobering reminder of the basic biology that still escapes the species count.

abyssal plain: the flat, mud-covered floor of the deep ocean

holocephalan: a group of cartilaginous fish that includes chimaeras (ghost sharks)

elasmobranch: the subgroup of cartilaginous fish that includes sharks and rays

bathypelagic: the dark deep-ocean zone between roughly 1,000 and 4,000 metres

biomineralised: produced by a living organism out of minerals it deposits

spicule: a small needle-like skeletal element, especially in sponges

symbiotic: involving a close biological relationship between two species

submersible: a small underwater vehicle designed to operate at great depths

Level 4 — Advanced

The Nippon Foundation-Nekton Ocean Census on Tuesday, May 19, 2026 announced the largest single-year yield in its short institutional history: 1,121 newly catalogued marine species, a 54 percent jump over the prior twelve months that nevertheless still illustrates, in the assessment of director Mitsuyuki Unno, how vast a fraction of the abyssal-bathypelagic realm remains untouched by formal taxonomy. The findings were collected across hydrothermal vent fields, tropical reef systems, polar continental margins, and the seamount chains that punctuate the Pacific, Atlantic and Indian basins, with several samples recovered from depths in excess of six kilometres.

The marquee organism is a previously undescribed holocephalan — colloquially a 'ghost shark' — imaged at roughly 820 metres by remotely operated vehicles in Australia's Coral Sea Marine Park. Holocephalans, sister taxon to the elasmobranchs (sharks, rays and skates), diverged from common ancestral chondrichthyans more than 300 million years ago. Their fused tooth-plate dentition, oversized photopic eyes optimised for the dim-light bathypelagic zone, and slow-glide ethology have made them an enduring object of curiosity since H.M.S. Challenger first dredged Chimaera monstrosa from the North Atlantic.

A separate cluster of Japanese teams contributed a startling commensal discovery from a volcanic Pacific seamount: a community of polychaete bristle worms colonising the chambered interior of a hexactinellid glass sponge. The sponge's skeleton, spun from biomineralised silica spicules into an iridescent latticework — the so-called 'glass castle' — appears to provide hydrodynamic shelter; pilot stable-isotope assays hint at a cleaning-and-detritus-recycling role for the worms reminiscent of cleaner-wrasse symbioses on shallower reefs. A follow-up sampling cruise this autumn will test the hypothesis with manipulative removal experiments.

The remainder of the 1,121-strong cohort spans cnidarians, crustaceans, echinoderms, gastropods, and a phylogenetically diverse parade of unfamiliar deep-sea fishes, alongside a striking population of roughly 30-centimetre porifera nicknamed 'death-ball' sponges by the descriptors. The headline statistic — that more than ninety percent of deep-ocean animal life remains undescribed — underscores the policy stakes attached to ongoing high-seas mining proposals and to upcoming negotiations under the BBNJ ('Biodiversity Beyond National Jurisdiction') treaty framework, which will set the rules under which industrial actors may operate over largely uninventoried ecosystems.

taxonomy: the scientific practice of classifying and naming organisms

chondrichthyan: any member of the class of jawed fish with cartilage skeletons, including sharks, rays and chimaeras

photopic: relating to vision adapted to low or specialised light environments

commensal: a biological relationship in which one organism benefits and the other is not significantly affected

hexactinellid: the group of glass sponges with skeletons of six-rayed silica spicules

stable-isotope assay: a laboratory technique that uses ratios of non-radioactive isotopes to infer diet or migration

cleaner-wrasse symbiosis: a partnership in which small wrasse fish remove parasites from larger reef fish

BBNJ: the United Nations treaty on Biodiversity Beyond National Jurisdiction governing the high seas

Level 1 — Absolute Beginner

Level 2 — Elementary

Level 3 — Intermediate

Level 4 — Advanced

Marine Scientists Identify a Record 1,121 New Ocean Species, Including a Deep-Sea Ghost Shark and a Glass-Sponge 'Castle' Off Japan

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