10-armed sea creature found lurking under rocks off Japan coast. It’s a new species

Off the coast of Japan, a colorful 10-armed sea creature tucked itself under a rock and waited. But its hiding place wouldn’t last long.

Divers flipped over the stone and spotted the unique animal. It turned out to be a new species.

Researchers spent over a decade surveying marine life off the coast of several islands in southern Japan, according to a study published Aug. 23 in the peer-reviewed journal J-STAGE. The effort involved scuba diving and dredging work.

Looking at their catch, researchers encountered several unfamiliar-looking feather stars, the study said. They took a closer look at these invertebrate animals and soon realized they’d discovered a new species: Nesometra integra, or the complete feather star.

Complete feather stars are considered “small-sized,” the study said. They have a small central body with 10 arms coming out of it, each measuring up to 1.6 inches in length. Smaller segments grow off each arm.

Overall, the new species looks almost like a pine tree branch, a photo shows.

Complete feather stars vary in color but generally have two main patterns: “solid” or “dotted,” the study said. The solid-colored animals have a uniform hue, ranging from purple to light brown to dark red. The dotted animals have a pale coloring covered in darker brown spots.

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Photos show the coloring of the new species. Both pattern variations seem to blend in well with the surrounding rock.

Complete feather stars were “found hiding below rocks during (the) daytime” and were only visible after the rock was flipped over, the study said. The animals typically lived between depths of about 60 to 360 feet.

Researchers said they named the new species after the Latin word “integra,” meaning “complete,” because of the shape of some of its small appendages.

So far, complete feather stars have been found near two island groups in southern Japan and one island in northwest Australia, the study said.

The new species was identified by its DNA, body shape and other subtle physical features, the study said.

The research team included Gregorius Pratama, Riccardo Virgili, James Reimer and Toshihiko Fujita.

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