Sex change and effective population size : implications for population genetic studies in marine fish
Coscia, I, Chopelet, J, Waples, R, Mann, B and Mariani, S 2016, 'Sex change and effective population size : implications for population genetic studies in marine fish' , Heredity, 117 , pp. 251-258.
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Large variance in reproductive success is the primary factor that reduces effective population size (Ne) in natural populations. In sequentially hermaphroditic (‘sex-changing’) fish, the sex ratio is typically skewed and biased toward the ‘first’ sex, while reproductive success increases considerably after sex change. Therefore, sex-changing fish populations are theoretically expected to have lower Ne than gonochorists (separate sexes), assuming all other parameters are essentially equal. In this study, we estimate Ne from genetic data collected from two ecologically similar species living along the eastern coast of South Africa: one gonochoristic, the ‘santer’ sea bream Cheimerius nufar, and one protogynous (female-first) sex-changer, the ‘slinger’ sea bream Chrysoblephus puniceus. For both species, no evidence of genetic structuring, nor significant variation in genetic diversity, were found in the study area. Estimates of contemporary Ne were significantly lower in the protogynous species, but the same pattern was not apparent over historical timescales. Overall, our results show that sequential hermaphroditism may affect Ne differently over varying time frames, and that demographic signatures inferred from genetic markers with different inheritance modes also need to be interpreted cautiously, in relation to sex-changing life40 histories.
|Schools:||Schools > School of Environment and Life Sciences > Ecosystems and Environment Research Centre|
|Journal or Publication Title:||Heredity|
|Publisher:||Nature Publishing Group|
|Funders:||Science Foundation Ireland|
|Depositing User:||Prof Stefano Mariani|
|Date Deposited:||06 Jun 2016 12:27|
|Last Modified:||14 Sep 2016 09:51|
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