title: Role of evolutionary and ecological factors in the reproductive success and the spatial genetic structure of the temperate gorgonian Paramuricea clavata.
abstract: Dispersal and mating features strongly influence the evolutionary dynamics and the spatial genetic structure (SGS) of marine populations. For the first time in a marine invertebrate, we examined individual reproductive success, by conducting larval paternity assignments after a natural spawning event, combined with a small-scale SGS analysis within a population of the gorgonian Paramuricea clavata. Thirty four percent of the larvae were sired by male colonies surrounding the brooding female colonies, revealing that the bulk of the mating was accomplished by males from outside the studied area. Male success increased with male height and decreased with increasing male to female distance. The parentage analyses, with a strong level of self-recruitment (25%), unveiled the occurrence of a complex family structure at a small spatial scale, consistent with the limited larval dispersal of this species. However, no evidence of small scale SGS was revealed despite this family structure. Furthermore, temporal genetic structure was not observed, which appears to be related to the rather large effective population size. The low level of inbreeding found suggests a pattern of random mating in this species, which disagrees with expectations that limited larval dispersal should lead to biparental inbreeding. Surface brooding and investment in sexual reproduction in P. clavata contribute to multiple paternity (on average 6.4 fathers were assigned per brood), which enhance genetic diversity of the brood. Several factors may have contributed to the lack of biparental inbreeding in our study such as (i) the lack of sperm limitation at a small scale, (ii) multiple paternity, and (iii) the large effective population size. Thus, our results indicate that limited larval dispersal and complex family structure do not necessarily lead to biparental inbreeding and SGS. In the framework of conservation purposes, our results suggested that colony size, proximity among colonies and the population size should be taken into consideration for restoration projects.
authors.affiliation: Institut National de Recherche Halieutique (INRH) 2 rue Tiznit, Casablanca, Morocco ; CNRS, UMR 7263 IMBE, Aix-Marseille Université Station Marine d'Endoume, Chemin de la Batterie des Lions, 13007, Marseille, France.
authors.forename: Kenza
authors.initials: K
authors.lastname: Mokhtar-Jamaï
authors.forename: Rafel
authors.initials: R
authors.lastname: Coma
authors.forename: Jinliang
authors.initials: J
authors.lastname: Wang
authors.forename: Frederic
authors.initials: F
authors.lastname: Zuberer
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Féral
authors.forename: Didier
authors.initials: D
authors.lastname: Aurelle
keywords: Gamete and larval dispersal; mating system; microsatellites; natural spawning event; parentage analyses