‘Strange’ sea creature with retractable tentacles is new species in Japan. See it
A “strange” creature recorded in the deep waters off the coast of Japan represents an exceptionally rare kind of discovery.
With a body shaped like Mount Fuji, the new-to-science sea anemone is not only a new species but is also part of a new genus and family, according to a study published June 18 in the journal Diversity.
To put that into perspective, it would be like someone discovering a new distinct branch of bird, like parrots or owls, and not just a new species within those groups.
The anemone, named Discoactis tritentaculata, or “umi-no-Fujisan,” which translates to “Mount Fuji of the ocean” in Japanese, is small, measuring just over half an inch in height, researchers said.
It starts out with 14 to 18 retractable tentacles, “striped with pale red and dark red,”but the anemone lose some as it matures, according to the study.
Its pedal, or the main part of its body, is semitransparent, flat and disc-like, researchers said.
Another distinct feature of the new species is that the tentacles around its mouth are arranged in “triplets,” or groups of three, unlike other anemone species.
The Mount Fuji of the ocean anemone was collected by trawlers and depths between 259 and 1,316 feet, according to the study.
Despite the rarity of the discovery, the species appears to be fairly common, with more than 10 of them collected from various waters, including the Pacific Ocean, Sagami-Bay, Suruga Bay, Otsuchi-Bay, Bungo Strait and the Sea of Japan, researchers said.
The research team included Takato Izumi, Kensuke Yanagi and Hisanori Kohtsuka.
This story was originally published June 20, 2025 at 6:11 AM with the headline "‘Strange’ sea creature with retractable tentacles is new species in Japan. See it."
