Genetic structure, bioenergetic responses and life history traits of European flounder populations (Platichthys flesus) under climate changes, over a latitudinal gradient
The European flounder (Platichthys flesus) is a catadromous fish species distributed along the North-East Atlantic coasts, from the Arctic polar circle to the Iberian Peninsula. For several decades, the southern limit of its distribution area is shifting towards the North of the Portuguese coast. A...
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Other Authors: | , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
Published: |
HAL CCSD
2016
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Subjects: | |
Online Access: | https://theses.hal.science/tel-01431379 https://theses.hal.science/tel-01431379/document https://theses.hal.science/tel-01431379/file/These-2016-EDSM-Biologie_marine-PEDRON_Nicolas.pdf |
Summary: | The European flounder (Platichthys flesus) is a catadromous fish species distributed along the North-East Atlantic coasts, from the Arctic polar circle to the Iberian Peninsula. For several decades, the southern limit of its distribution area is shifting towards the North of the Portuguese coast. A preliminary study on the flounder population biology has detected a specific energetic metabolism for a southern peripheral population in Portugal compared to Northern populations located in the Bay of Biscay and in the Channel. In the present study, we have combined population genetics with experimental challenges in the laboratory to improve our knowledge on the genetic structure of flounder populations over Europe, and on the potentially resulting phenotypic differences among populations, mainly considering bioenergetics and life-history traits. The polymorphism of microsatellite markers and of several candidate genes highlighted a significant genetic differentiation between Iberian Peninsula populations and Northen populations. A thermal and hypoxia challenge has been conducted on flounder juveniles, considering (1) enzymatic activities linked to energetic metabolism (aerobiosis and anaerobiosis) and anabolism, and (2) a proteomic approach; this common garden experiment suggested a higher capacity of central populations (from Canche and Vilaine, France) and of one peripheral Southern population (from Lima, Portugal) to cope with respectively cold condition, warm and hypoxia condition. Finally, the analysis of thermal reaction norms in fish early life history traits, considering embryo-larval stages submitted to a thermal gradient, underlined a possible local adaptation of the flounder populations to their thermal environments. Le flet européen (Platichthys flesus) est un poisson catadrome dont l’aire de répartition dans le Nord-Est Atlantique s’étend du cercle polaire Arctique jusqu’au Portugal. Depuis quelques décennies, la limite Sud de son aire de distribution remonte le long des côtes Portugaises. Une étude ... |
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