Genetic structure and demographic inference of the regular sea urchin Sterechinus neumayeri (Meissner, 1900) in the Southern Ocean: the role of the last glaciation

• Published in: PLOS ONE
• Main Authors: Díaz, Angie, Gérard, Karin, González-Wevar, Claudio, Maturana, Claudia, Feral, Jean-Pierre, DAVID, Bruno, Saucède, Thomas, Poulin, Elie
• Other Authors: Departamento de Zoología, Universidad de Concepción Chile, Facultad de Ciencias, Universidad de Magallanes (UMAG), Laboratorio de Ecología Molecular Antártica y Subantártica, Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Instituto de Ecología y Biodiversidad (IEB), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement IRD : UMR237-Centre National de la Recherche Scientifique (CNRS), Biogéosciences UMR 6282 Dijon (BGS), Centre National de la Recherche Scientifique (CNRS)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Muséum national d'Histoire naturelle (MNHN), Study funded by different projects and institutions including INACH D 05–09 and Conicyt Ph.D. Grant (D-21080136).
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Antarctica; Haplotypes; Phylogeography; Population genetics; Genetic loci; Islands; Species diversity; Antarctic Ocean; [SDV.GEN.GPO]Life Sciences [q-bio]/Genetics/Populations and Evolution [q-bio.PE]; Antarctic; Antarctic Peninsula; East Antarctica; Southern Ocean; The Antarctic; Weddell; Weddell Sea; Antarc*
• Online Access: https://hal.archives-ouvertes.fr/hal-01821689; https://hal.archives-ouvertes.fr/hal-01821689/document; https://hal.archives-ouvertes.fr/hal-01821689/file/journal.pone.0197611.pdf; https://doi.org/10.1371/journal.pone.0197611

22 pages International audience One of the most relevant characteristics of the extant Southern Ocean fauna is its resiliency to survive glacial processes of the Quaternary. These climatic events produced catastrophic habitat reductions and forced some marine benthic species to move, adapt or go extinct. The marine benthic species inhabiting the Antarctic upper continental shelf faced the Quaternary glaciations with different strategies that drastically modified population sizes and thus affected the amount and distribution of intraspecific genetic variation. Here we present new genetic information for the most conspicuous regular sea urchin of the Antarctic continental shelf, Sterechinus neumayeri. We studied the patterns of genetic diversity and structure in this broadcast-spawner across three Antarctic regions: Antarctic Peninsula, the Weddell Sea and Adélie Land in East Antarctica. Genetic analyses based on mitochondrial and nuclear markers suggested that S. neumayeri is a single genetic unit around the Antarctic continent. The species is characterized by low levels of genetic diversity and exhibits a typical star-like haplotype genealogy that supports the hypothesis of a single in situ refugium. Based on two mutation rates standardized for this genus, the Bayesian Skyline plot analyses detected a rapid demographic expansion after the Last Glacial Maximum. We propose a scenario of rapid postglacial expansion and recolonization of Antarctic shallow areas from a less ice-impacted refugium where the species survived the LGM. Considering the patterns of genetic diversity and structure recorded in the species, this refugium was probably located in East Antarctica.