Persistent unequal sex ratio in a population of grayling (salmonidae) and possible role of temperature increase.

Détails

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Etat: Serval
Version: Author's accepted manuscript
ID Serval
serval:BIB_E61D44BFF676
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Persistent unequal sex ratio in a population of grayling (salmonidae) and possible role of temperature increase.
Périodique
Conservation Biology
Auteur(s)
Wedekind C., Evanno G., Székely T., Pompini M., Darbellay O., Guthruf J.
ISSN
1523-1739 (Electronic)
ISSN-L
0888-8892
Statut éditorial
Publié
Date de publication
2013
Peer-reviewed
Oui
Volume
27
Numéro
1
Pages
229-234
Langue
anglais
Résumé
In some fishes, water chemistry or temperature affects sex determination or creates sex-specific selection pressures. The resulting population sex ratios are hard to predict from laboratory studies if the environmental triggers interact with other factors, whereas in field studies, singular observations of unusual sex ratios may be particularly prone to selective reporting. Long-term monitoring largely avoids these problems. We studied a population of grayling (Thymallus thymallus) in Lake Thun, Switzerland, that has been monitored since 1948. Samples of spawning fish have been caught about 3 times/week around spawning season, and water temperature at the spawning site has been continuously recorded since 1970. We used scale samples collected in different years to determine the average age of spawners (for life-stage specific analyses) and to identify the cohort born in 2003 (an extraordinarily warm year). Recent tissue samples were genotyped on microsatellite markers to test for genetic bottlenecks in the past and to estimate the genetically effective population size (N(e) ). Operational sex ratios changed from approximately 65% males before 1993 to approximately 85% males from 1993 to 2011. Sex ratios correlated with the water temperatures the fish experienced in their first year of life. Sex ratios were best explained by the average temperature juvenile fish experienced during their first summer. Grayling abundance is declining, but we found no evidence of a strong genetic bottleneck that would explain the apparent lack of evolutionary response to the unequal sex ratio. Results of other studies show no evidence of endocrine disruptors in the study area. Our findings suggest temperature affects population sex ratio and thereby contributes to population decline. Persistencia de Proporción de Sexos Desigual en una Población de Tímalos (Salmonidae) y el Posible Papel del Incremento de la Temperatura.
Mots-clé
effective population size, environmental sex reversal, monitoring, operational sex ratio, sex-biased mortality
Pubmed
Web of science
Open Access
Oui
Création de la notice
30/04/2012 10:19
Dernière modification de la notice
09/05/2019 2:42
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