A new gorgonian Pseudopterogorgia nanjiensis sp. nov. (Cnidaria, Octocorallia, Gorgoniidae) from the Nanji Islands, China

Members of the genus <i>Pseudopterogorgia</i> Kükenthal, 1919 are widely distributed in shallow water of the Indo-West Pacific. During an investigation of benthic biodiversity in the subtidal zone surrounding the Nanji Islands in the East China Sea, two specimens of <i>Pseudopterogorgia</i> were collected and described as a new species based on an integrated morphological-molecular approach. <i>Pseudopterogorgiananjiensis</i> <b>sp. nov.</b> is most similar to <i>P.fredericki</i> Williams & Vennam, 2001 in the irregular branching form and indistinct scaphoids, but differs by the coenenchymal sclerite content of distinct capstans and a few warty spindles and radiates (vs. mostly warty spindles and a few capstans), and a purplish colony (vs. white, pink to deep rose). Molecular phylogenetic analyses, based on the mtMutS-COI gene sequences, delineated a monophyletic clade encompassing all assessed <i>Pseudopterogorgia</i> species. Within this clade, <i>P.nanjiensis</i> <b>sp. nov.</b> showed a close phylogenetic affinity with both <i>P.fredericki</i> and <i>P.australiensis</i> Ridley, 1884.