The scientific publication describes 17 new species of Polychaeta also known as bristle worms, a class which is a close cousin of the well-known earth worm found in your garden. The worms were found at a depth between 4000 et 5000 m in the so-called Clarion-Clipperton Fracture Zone (CCFZ). The area, which is targeted for deep-sea mining, is home of the largest polymetallic nodule field in the world, with ~6 million km2 of seabed covered with nodules containing manganese, nickel and cobalt.
The records of polychaetes in this region are scarce. Data gathered during the JPI Oceans MiningImpact project made a significant contribution to fill this gap, with five different localities sampled between 4000 and 5000 m depth in 2015. A large collection of deep-sea polynoids collected during the cruise SO239 led to the discovery of ~80 molecular operational taxonomic units (or potential species) and, for the first time ever, enabled researchers to provide insights into the evolution of this poorly understood group.
The family Polynoidae is one of six families of scale-worms. In their search to name some of the new species the scientists drew inspiration from the well know TV series Game of Thrones. Abyssarya acus is named after Arya Stark while the Hodor hodor is now known under the name of another key character in the series. Likewise, another species is named Yodanoe desbruyeresi, after the Grand Master of the Jedi Order, Yoda, in the Star Wars saga.
In the article the scientists confirms the high biodiversity in the manganese nodule field, specifically for polynoids. Paulo Bonifácio, post-doc at the deep-sea environment lab at the French research institute Ifremer says: “it is area of which we still know very little about. In every sample taken from the abyss, we found new species. While we could have described up to a 70 new species, we focused our work on the 17 species which were best preserved.” Polynoids are just one among the 42 families of polychaetes which can be sampled in the CCFZ.
A key finding of the MiningImpact project is that the habitat formed by manganese nodules is home to specific fauna. The abundance of species and their diversity is related to the nodule density of the seafloor. “In the zone where the seafloor was disturbed by a deep-sea mining simulation experiment, the impact is still visible and the fauna has not fully recovered, even after thirty years,”; says Lénaïck Menot, co-author of the article.
- Paulo Bonifácio, Lénaïck Menot; New genera and species from the Equatorial Pacific provide phylogenetic insights into deep-sea Polynoidae (Annelida), Zoological Journal of the Linnean Society.