Data/hora: 04/06/2024 15:38:30

Provedor de dados: 	5	
País: 	France	
Título: 	Modélisation basée sur la théorie des budgets d’énergie dynamiques (DEB) de la cinétique de bioaccumulation des toxines paralysantes (PST) par l’huître creuse Crassostrea gigas	
Autores: 	Pousse, Emilien.	
Data: 	2017-12-21	
Ano: 	2017	
Palavras-chave: 	Budgets d’Énergie Dynamiques; Toxines paralysantes; Pacific oyster; Cinétiques d’accumulation; Écotoxicologie; Dynamic Energy Budget; Paralytic Shellfish Toxins; Pacific oyster; Accumulation kinetics; Ecotoxicology.	
Resumo: 	The oyster Crassostrea gigas is one of the most commercialized molluscs in the world. It is a very cosmopolitan species that has been disseminated by humans and is susceptible to various agents such as pathogens (bacteria, viruses), parasites, xenobiotics and/or toxic micro-algae. As a filter-feeder, it may accumulate phyco- toxins while feeding on harmful algal blooms (HAB), including paralytic shellfish toxins (PST). To protect human health shellfisheries harvesting are closed dur- ing HAB, impacting the aquaculture industry. This PhD work aims to develop a Dynamic Energy Budget (DEB) based model to describe kinetics of PST accumulation and detoxification in C. gigas. Interest of coupling bio-accumulation to DEB model lies in the inclusion of physiological (e.g. body size, tissue composition) and environmental (food quantity and quality) variables to simulate accurately the dynamics of contaminants in marine organisms. Two experiments consisting in exposing C. gigas to the toxic dinoflagellate Alexandrium minutum were performed. Toxin intake was calibrated in a first short-term experiment where clearance rates and assimilation efficiency were individually measured during an exposure to toxic and non-toxic micro-algae. Metabolic rates (respiration, cardiac activity) were also assessed. This study brings new insights concerning the important inter-individual variability of PST accumulation reported in C. gigas by identifying three phenotypes characterized by different clearance rates. Then a long-term exposure to a mixture of toxic and non-toxic micro-algae was carried out to calibrate (1) toxin elimination process, (2) PST effects on oyster bioenergetic and (3) validate a mathematical representation of particles selection. A DEB model simulating the evolution of toxin concentration via two compartments (unassimilated and assimilated toxins) is proposed which was validated using a laboratory dataset and field surveys. In a last part, the numerical model is then used to investigate the differences in toxification and depuration dynamics between diploid and triploid oysters. Results allowed to confirm hypothesis stating that triploids accumulate generally more than diploids but also showed that spawning could inverse this trend. 	
Tipo: 	Text	
Idioma: 	Francês	
Identificador: 	http://archimer.ifremer.fr/doc/00456/56792/58631.pdf

http://archimer.ifremer.fr/doc/00456/56792/	
Editor: 	Université de Bretagne Occidentale	
Formato: 	application/pdf	
Fonte: 	2017 UBO

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