Japanese scientists find a new species of sea worm one millimeter wide at almost 2,500 meters deep.

The new species, named Flabelligena hakuhoae, now joins the other six species that belong to the genus.

Earlier this year, a team from the National Polar Research Institute (NIPRJapan, the National Museum of Nature and Science and Kochi University set out to collect specimens of sea worms near the South Orkney Islands, a remote region of the Southern Ocean more than 640 km to the northeast of the tip of the antarctic peninsula.

The researchers collected material from the seabed at depths between 2,036 and 2,479 meters, in an area known as bathyal, which extends from 1,000 to 4,000 meters deep. The results of the analysis were recently published in the Biodiversity Data Journal.

Among the collected material, biologists identified a tiny worm, new to science, which they called Flabelligena hakuhoae. Thanks to the description of the invertebrate through a scanning electron microscope, the scientists deduced that the new species belonged to a family of polyquetos containing more than 10,000 species.

“Polychaetes are one of the most diverse groups of marine benthic animals and are well studied in the Antarctic Ocean,” he explains. Naoto Jimi, leader of the work and postdoctoral member of the National Polar Research Institute. Although many researchers have studied this ocean, “our knowledge of small deep-sea invertebrates is still quite limited,” Jimi emphasizes.

First worm of its kind in the Antarctic

According to the analysis of the team of scientists, the microscopic marine worm – 1.8 cm long and 1 mm wide – had small rounded protrusions (body papillae), one to three pairs of gills and other frontal gills associated with touch and taste. Both ends of the polychaete, preserved in formaldehyde, are rounded.

The new species of worm now joins the other six species described in the genus Flabelligena, mainly known in the North Atlantic Ocean, but also present in the Mediterranean or the southern Indian Ocean. All of them live in areas of sandy mud, especially in the bathyal area at depths of more than a thousand meters.

Flabelligena hakuhoae It is then the first species of this genus to be recorded in the Antarctic Ocean. For this reason, Jimi and his team consider this finding will contribute “spectacularly” to the understanding of biodiversity from the Antarctic region.

Biologists now hope to discover more species and continue learning about this vast ocean. “This is only the first step to understand the biodiversity of the Antarctic”, underlines the Japanese scientist.

“The next step will be to understand the diversity of polychaetes around the Syowa research station, located on eastern Ongul Island two kilometers from the Antarctic continent,” concludes the researcher.