38 new species found near Japan

The deep sea off Japan just got a lot less empty. Scientists have now confirmed 38 new species from a June 2025 expedition to the Nankai Trough and the Shichiyo Seamount Chain, with another 28 candidates still being checked. That sounds like a quirky natural-history story — weird jelly blobs, glass sponges, alien worms — but the real point is bigger. We are still doing first-pass inventory work in huge parts of the ocean, and one expedition can still blow up the baseline. ### Who actually found them? This came out of a joint effort between the Nippon Foundation–Nekton Ocean Census and JAMSTEC, Japan’s big marine science agency. The fieldwork happened in June 2025 aboard the research vessel *Yokosuka*, with dives supported by the crewed submersible *Shinkai 6500*. The team collected more than 528 specimens, then spent months cataloging, imaging, preserving, and comparing them before taxonomists met in Yokosuka in October 2025 to sort out which ones were genuinely new. (oceancensus.org) ### Where were they looking? Two places — and both matter. The Nankai Trough sits roughly 500 to 600 kilometers southwest of Tokyo and is one of Japan’s most geologically active deep-sea zones. The Shichiyo Seamount Chain lies about 500 to 700 kilometers southeast of Tokyo and is a line of underwater volcanic mountains. These are not easy places to sample, which is part of why the biodiversity picture was so incomplete. (oceancensus.org) ### Why is the Nankai Trough result such a big deal? Because the species count there jumped from 14 known cold-seep animal species to 80. That is the five-fold increase people keep highlighting. Cold seeps are deep-ocean habitats where methane and other chemicals leak from the seafloor, letting ecosystems run on chemosynthesis instead of sunlight. Basically, if your old map said “14 things live here” and one serious survey says “actually it’s 80,” your old map was barely a sketch. (oceancensus.org) ### What’s the “glass castle” part? One of the standout finds was a new glass sponge species hosting multiple polychaete worm species inside its rigid silica skeleton. That is where the “glass castle” line comes from. The worm study, led by Naoto Jimi, highlighted species including *Dalhousiella yabukii* and *Leocratides watanabeae*, which appear to have evolved around this sponge-based lifestyle. It is a good reminder that new species are only half the story — new ecological relationships can be just as important. (oceancensus.org) ### Were these all giant monster animals? No — and that is part of the point. Some are visually dramatic, like glass sponges and gelatinous animals, but biodiversity jumps often come from careful work on small invertebrates that most people would never notice in a photo. Mollusks, annelids, arthropods, nemerteans, echinoderms, cnidarians, and even a bryozoan turned up in the Nankai seep survey. The deep sea looks sparse from the surface, but turns out it is often just undersampled. (newsbreak.com) ### Why does this matter beyond cool pictures? Because you cannot protect what you have not even named. Deep-sea regions are increasingly relevant to conservation, fisheries, seabed industry, and basic Earth-system science. If a single expedition can confirm 38 new species and flag 28 more, that suggests the discovery curve is still steep. In plain English — we are making decisions about the ocean while still missing a lot of the cast list. (oceanographicmagazine.com) ### So what happens next? The exciting images come first, but taxonomy moves slower. The confirmed species will feed into formal papers and reference collections, and the 28 “potential new species” still need more morphological and molecular work. That lag is normal. Discovery in the deep sea is not just about seeing something strange on a dive — it is about proving, carefully, that nobody has described it before. (oceancensus.org) ### Bottom line? The headline is 38 new species near Japan. But the deeper story is that the ocean is still full of places where the first serious look changes everything. (oceancensus.org)