Mating system and evidence of multiple paternity in the Antarctic brooding sea urchin Abatus agassizii.

• Published in: Polar Biology
• Main Authors: Maturana, Claudia S., Gérard, Karin, Díaz, Angie, David, Bruno, Feral, Jean-Pierre, Poulin, Elie
• Other Authors: Instituto de Ecología y Biodiversidad (IEB), GAIA-Antártica, Universidad de Magallanes (UMAG), Departamento de Zoología, Universidad de Concepción - University of Concepcion Chile, Biogéosciences UMR 6282 (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN), 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), Study supported by the Grants PFB-23 and ICM P05-002 and Thesis project INACH M02_10 and CONICYT PhD 21150317; INACH D05-09, FP_03-12, CONICYT Ph.D.D-21060218, D21-08 and Postdoctoral FONDECYT 3130677, Fondecyt post-doctorate 3100139 and INACH F01_09, and Egide program ECOS-Sud C06B02., PROTEKER
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: Parentage analysis; Polyandry; Spermcast; Vagility; Panmixia; Southern Ocean; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.EE.IEO]Life Sciences [q-bio]/Ecology; environment/Symbiosis; Antarctic; The Antarctic; Antarc*; Polar Biology
• Online Access: https://hal.science/hal-01516148; https://doi.org/10.1007/s00300-016-2001-3

11 pages International audience Broadcasting is the predominant spawning behavior among benthic marine invertebrates, mainly associated with planktotrophic and planktonic lecitotrophic development. Broadcasting allows genetic mixing that should contribute to increase the genetic diversity of a female clutch. Conversely, in brooding species characterized by protected development, oocytes are retained and only sperm is released, which is supposed to limit the number of males that contribute to a female clutch. This spermcasting behavior together with egg retention, unusually frequent among Antarctic marine invertebrates, putatively give brooders low dispersal capacities which may reduce genetic mixing and generate genetic and kinship structure at a small spatial scale. Like many other Antarctic marine benthic invertebrates, the irregular sea urchin Abatus agassizii is a spermcaster that broods its young. In this study, we assessed the genetic diversity among 66 adults using 6 polymorphic microsatellite loci and performed progeny array analyses in order to evaluate the number of mates per female as well as genetic structure at a small spatial scale. A. agassizii exhibited a polyandric system with 2–5 mates per female regardless of population density. Bayesian analyses suggested the absence of genetic structure along our 20-m transect, while relatedness among individuals did not differ from that expected under panmixia. Finally, we conclude that a limited number of males contribute to a female clutch, probably as a consequence of limited sperm dispersal and that movement of adults may be sufficient to avoid kinship structure in the population.