A new genus of bamboo coral (Octocorallia: Scleralcyonacea: Keratoisididae) from the Whittard Canyon, Ireland, Northeast Atlantic

Deep-sea corals are rarely identified to species due to a lack of taxonomic expertise and paucity of sampling. Herein we describe a new genus from the family Keratoisididae collected from the Northeast Atlantic. Using both nuclear (2010 conserved element loci) and complete mitogenome phylogenies, we found this genus to be closely related to the genera Dokidisis and Jasonisis. In the nuclear phylogeny, each genus occupied a distinct well-supported clade. All three genera lack thorned- or double-star sclerites in the pharynx; instead they have flattened rods, a potential unifying feature of the keratoisidid group J3 of Watling et al. (2022). The newly described genus Explorisis gen. nov. has a unique sclerome including spindles and tapered rods that differentiates it from its sister genera. Explorisis katharina sp. nov. is characterised by volcano to cylindrical shaped polyps, striated rods and spindles in the polyp body, and elongated flattened rods in the coenenchyme, whereas Explorisis poppyae sp. nov. has heavily granulated spindles and rods in both the polyp body and coenenchyme. Genetic variation within the mitogenomes across both Explorisis gen. nov. species is limited with mutations in just 3 of 14 protein coding regions.ZooBank: urn:lsid:zoobank.org:pub:141BD76E-8C83-43BE-8E1E-B8C53CD7CEF7 Deep-sea corals are often not identified to species rank due to a lack of taxonomic expertise. Bamboo corals are an exclusively deep sea and prolific group of corals found in every ocean basin. In this study, we describe a new genus and two new species of bamboo coral from the Northeast Atlantic. By analysing both their morphology and DNA, we determined that this newly identified genus, named Explorisis, is closely related to the genera Dokidisis and Jasonisis. (Image credit: Declan Morrissey.)