Granulogorgia is a recently established monotypic genus phylogenetically classified into Acanthogorgiidae by the mtMutS gene. To confirm its systematic position, we investigated the taxonomy and phylogeny of two relative specimens using an integrative taxonomic approach combining morphology, mtMutS, 28S rDNA and ultraconserved element (UCE) phylogenomics. One specimen represents a new species of Granulogorgia, G. jiani sp. nov., which is characterized by calicular thorn scales along with coenenchymal branched plates. The second specimen is described as a new genus and species, Spinagorgia gibbosa gen. et sp. nov., which can be distinguished by its large thorn scales in both the calyx wall and coenenchyme. The UCE phylogenomics and mtMutS topology are both recovering the two taxa as a distinct clade within Acanthogorgiidae. Moreover, mtMutS outperforms 28S rDNA for distinguishing species of Granulogorgia-Spinagorgia lineage. Despite their close phylogenetic affinity, the two genera exhibit pronounced differences in the morphology of their calicular and coenenchymal sclerites. This discordance between genetic relatedness and morphological divergence underscores the necessity of integrative taxonomy and phylogenomic analyses within Acanthogorgiidae.
Granulogorgia jiani sp. nov., Spinagorgia gibbosa gen. et sp. nov., Deep-sea coral, Phylogenomics, Ultraconserved elements
