Seven snail species hidden in one: biogeographic diversity in an apparently widespread periwinkle in the Southern Ocean.

• Published in: Journal of Biogeography
• Main Authors: González-Wevar, Claudio A., Segovia, Nicolás I., Rosenfeld, Sebastián, Maturana, Claudia S., Jeldres, Vanessa, Pinochet, Ramona, Saucède, Thomas, Morley, Simon A., Brickle, Paul, Wilson, Nerida G., Spencer, Hamish G., Poulin, Elie
• Other Authors: Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Biodiversidad de Ecosistemas Antárticos y Subantárticos (BASE), Instituto Milenio de Biología Integrativa = Millennium Institute for Integrative Biology (iBio), Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Departamento de Ciencias Ecológicas, Departamento de Biología Marina Coquimbo, Universidad Católica del Norte Antofagasta, Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Universidad de Magallanes, Biogéosciences UMR 6282 (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), South Atlantic Environmental Research Institute UK, Falkland Islands Joint Nature Conservation Committee UK, School of Biological Sciences Aberdeen, University of Aberdeen, Western Australian Museum (WAM), The University of Western Australia (UWA), Department of Zoology, University of Otago Dunedin, Nouvelle-Zélande, This study was funded ANID – Millennium Science Initiative Program– ICN2021_002, FONDAP IDEAL (15150003), GAB PIA CONICYTACT172065, INACH Project RG_18-17, Program PR-06-CRN-18,ANID/BASAL FB210018, PIA CONICYT AFB170008 (IEB), FondecytPostdoctoral 3210063 and Fondecyt Regular Project 1210787.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Antarctic; cryptic species; dispersal; Littorinidae; species-delimitation analyses; sub-Antarctic; vicariance; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Southern Ocean; The Antarctic; Antarc*; Antarctica
• Online Access: https://hal.archives-ouvertes.fr/hal-03759101; https://doi.org/10.1111/jbi.14453

14 pages International audience AimThe Antarctic Circumpolar Current imparts significant structure to the Southern Ocean biota. The Antarctic Polar Front is a major barrier to dispersal, with separate species (or sometimes intraspecific clades) normally occurring either side of this feature. We examined the biogeographic structure of an apparent exception to this rule in a widespread genus of the Southern Ocean, the periwinkle snail, Laevilitorina.LocationSouthern Ocean.TaxonLittorinidae, Laevilitorininae, Laevilitorina.MethodsUsing 750 specimens from 16 Southern Ocean Laevilitorina populations across >8000 km, we analysed mitochondrial COI and nuclear 28S sequences to uncover the evolutionary history of these marine near-shore snails. We utilized multi-locus phylogenetic reconstructions, species-delimitation analyses, divergence-time estimations and geometric morphometrics.ResultsMolecular data revealed that the widespread nominal species L. caliginosa comprises seven species-level clades, all supported by morphological data, whereas the Antarctic nominal species L. antarctica, L. claviformis and L. umbilicata are conspecific. Six “caliginosa” clades are restricted to southern South America, but one lineage extends from Antarctica to distant sub-Antarctic islands on both sides of the APF. Geometric morphometrics also identified significant differences among these clades, but uncoupled from genetic differentiation.Main conclusionsThe apparent trans-APF distribution of the poorly dispersing Laevilitorina caliginosa is largely illusory: this taxon consists of at least seven discrete species, only one of which has a trans-APF distribution. Similar to most Laevilitorina species, the remaining six “caliginosa” clades are narrow endemics. Biogeographical patterns in Laevilitorina reflect the role of vicariance associated with geological processes together with recent long-distance dispersal events. Laevilitorina originated near the Eocene/Oligocene boundary and diversified during the Miocene and the Pliocene. ...