Given the scientific name Clavelina ossipandae, scientists discovered that it was a new species of sea squirt after divers posted images of it online. Naohiro Hasegawa, a researcher at Hokkaido University and co-author of the study that first described the species in the journal Species Diversity, told Reuters: “The white parts that look like bones are the blood vessels that run horizontally through the sea squirts’ gills. The black parts on the head that look like a panda’s eyes and nose are just a pattern, and we don’t really know why the pattern is there.” 

When photos of these unusual critters first surfaced online in 2017, researchers saw some photos that a dive center had posted and came to the realization that the species might be new to science. After analyzing specimens that had been collected by divers on a crowdfunded expedition, the scientists confirmed that this type of sea squirt had never been described before. 

Researchers describing the new species named the animal “gaikotsu-panda-hoya,” which means “skeleton panda ascidian,” for their distinctive markings, which give it the appearance of a bony body with a panda face and a gaping mouth. The first part of the scientific name in Latin, Clavelina, means “little bottle” and the second part, ossipandae, combines the Latin “os” (which means "bone") and “panda.”

Less than an inch long (20mm), skeleton pandas, like other sea squirts, are filter-feeding marine invertebrates. Found in shallow waters of up to 66ft (20m), they anchor themselves to the substrate of coral reefs with strong currents and filter nutrients from the water by pumping water through their siphons. Living in colonies of one to four individuals, they can reproduce asexually through budding but are also hermaphroditic and are capable of sexual reproduction.