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

Three new cave-dwelling aeglid species from the Alto Ribeira karst region, south-eastern Brazil, are described. Morphological descriptions are based on traits traditionally used in aeglid taxonomy. Molecular phylogeny reconstruction based on the partial fragments of the 16S ribosomal RNA (16S rDNA) and the cytochrome oxidase subunit I (COI) revealed that: (1) dispersal of epigean aeglids toward the Alto Ribeira karst area occurred at two separate events in the evolutionary history of freshwater aeglids; (2) extant cave-dwelling aeglid species form two distinct subclades, each of which originated from a distinct ancestral epigean lineage; and (3) successful adaptation to subterranean habitats, as seen in extant cave-dwelling aeglid species from the Alto Ribeira karst area, developed independently within each subclade, as each one of them comprised an exclusive group of both stygobitic and stygophilic species.

ZooBank: urn:lsid:zoobank.org:pub:3F2D0A63-B86E-421F-9B29-DD605BF7B4E7