Systematic revision of Nacella (Patellogastropoda: Nacellidae) based on a complete phylogeny of the genus, with the description of a new species from the southern tip of South America.

• Published in: Zoological Journal of the Linnean Society
• Main Authors: González-Wevar, Claudio A., Hüne, Mathias, Rosenfeld, Sebastián, Nakano, Tomoyuki, Saucède, Thomas, Spencer, Hamish, Poulin, Elie
• Other Authors: Laboratorio de Ecología Molecular Antártica y Subantártica, Universidad de Magallanes (UMAG), Instituto de Ecología y Biodiversidad (IEB), Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Universidad Austral de Chile, Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Seto Marine Biological Laboratory, Kyoto University-Field Science Education and Research Centre, Biogéosciences UMR 6282 (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Department of Zoology Dunedin, University of Otago Dunedin, Nouvelle-Zélande
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Antarctica; biogeography; COI mtDNA; Miocene; molecular phylogeny; Mollusca; morphology; Patagonia; phylogenetic systematic; rRNA; [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics; Phylogenetics and taxonomy; Antarctic; Nacella; Southern Ocean; The Antarctic; Antarc*
• Online Access: https://hal.science/hal-02456211; https://doi.org/10.1093/zoolinnean/zly067

34 pages International audience True limpets of the genus Nacella (Patellogastropoda: Nacellidae) include at least 11 nominal species distributed in different provinces of the Southern Ocean. Here, we present new molecular analyses and a comprehensive morphological revision of Nacella confirming the validity of all the currently recognized species, but with important amendments to the published distributions of several. We also show that specimens collected along two fjords in the Beagle Channel, southern South America, constitute a new taxon: Nacella yaghana sp. nov. The phylogenetic position of this new taxon in our molecular tree reveals that it represents an ancestral South American lineage of Nacella, markedly separated from the previously recognized and evolutionary recent Magellanic radiation. In addition, this new Nacella species was clearly distinguished from the rest of the species by morphological comparisons, including shell characteristics, radular-tooth shape and configuration, as well as by the coloration pattern of the mantle tentacles. This study provides new evidence about the evolutionary history of this important Southern Ocean, marine, near-shore benthic group and the role of the Antarctic Circumpolar Current in the biogeography of the genus.