Data/hora: 01/06/2024 06:44:25

Provedor de dados: | 5
País: | France

Título:

Conséquences à long terme d'une exposition précose à l'hypoxie sur la physiologie du bar européen (Dicentrarchus labrax) et de la sole commune (Solea solea)

Long-term consequences of early exposure to hypoxia on the physiology of European sea bass (Dicentrarchus labrax) and common sole (Solea solea)

Autores: | Vanderplancke, Gwenaelle.
Data: | 2015-02-12
Ano: | 2015
Palavras-chave: | Hypoxie; Conditionnement; Programmation environnementale; Poissons marins; Changement climatique; Oxygène; Dicentrarchus labrax; Solea solea; Marine fish; Climate change; Oxygen; Hypoxia; Conditioning; Environmental programming.
Resumo: | The dissolved oxygen in seawater has steadily declined in many coastal marine ecosystems in the last 50 years because of global warming and increasing coastal human activities. This decrease in oxygen in seawater causes episodes of hypoxia increasingly frequent and severe in coastal and estuarine areas. Some organisms may escape these environmental constraints by migration or dispersion. Others, with limited swimming capabilities must implement physiological regulation (phenotypic plasticity) to enable them to adapt and survive. This is particularly the case of marine fish larvae that are likely to be present in coastal nursery at the end of their development. It is now well established that the regulations implemented by organisms to cope with their environment during the early stages of life can imprint their physiological function in the long-term and change their life trajectory. While much information on early conditioning is available in the field of medicine, knowledge of these effects in marine organisms in an ecological context are still very fragmentary. Therefore, the main objective of this thesis was to evaluate the physiological consequences, not only in the short-term but especially in the long-term, of an exposition to a moderate hypoxia (8 days, 40% air saturation) of marine fish at the end of larval development. Another originality of this work was based on the comparison of adaptive responses implemented in two species, one pelagic ─ European sea bass (Dicentrarchus labrax) ─ and one benthic ─ the common sole (Solea solea). Our results have allowed us to show a significant long-term effect of early hypoxic stress on the physiological performance of juvenile and especially their growth. Juveniles of European sea bass and juveniles of common sole have, respectively, lower and higher growth after being exposed to a hypoxic environment in the larval stage. The negative effect on growth observed in sea bass was due, in part, to lower energy assimilation as a consequence of an impact on the digestive function. Moreover, molecular analyzes in the liver of sea bass juveniles indicate an impregnation at the transcriptional level of the expression of genes involved in the response to hypoxia. The positive effect observed on the growth of sole juveniles is associated with better tolerance to thermal and hypoxic stress and a decrease in metabolic scope. The results obtained in European sea bass and common sole suggest that changes in energy allocations could explain the physiological performances observed in the long-term. Globally, all the data obtained in this thesis underline the importance of the environmental parameters encountered by fish during their young life stages on their future physiological performances. Such physiological impregnation by the early environment is species-specific, revealing potential different adaptation strategies.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00498/60938/64332.pdf

https://archimer.ifremer.fr/doc/00498/60938/

Editor: | Université de Bretagne occidentale
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

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