Data/hora: 06/06/2024 03:26:27

Provedor de dados: | 5
País: | France

Título:

Études écophysiologiques sur Dinophysis et sa chaîne alimentaire, et effets in vitro du dinoflagellé et de ses toxines sur les premiers stades de vie de deux modèles d'animaux marins (l’huître et le poisson)

Ecophysiological studies on Dinophysis and its food chain, and in vitro effects of the dinoflagellate and its toxins on early life stages of two models of marine animals (oyster and fish)

Autores: | Gaillard, Sylvain.
Data: | 2020-11-27
Ano: | 2020
Palavras-chave: | Changement global; Crassostrea gigas; Cyprinodon variegatus; Dinophysis; Efflorescences; Mesodinium; Pecténotoxines; Teleaulax; Toxines diarrhéiques; Crassostrea gigas; Cyprinodon variegatus; Diarrheic toxins; Dinophysis; Global change; Harmful algal blooms; Mesodinium; Pectenotoxins; Teleaulax.
Resumo: | Harmful algal blooms of Dinophysis are responsible for diarrheic shellfish poisoning in human consumers of contaminated mollusks after bioaccumulation of their toxins. Dinophysis is a mixotrophic organism, which sequesters chloroplasts from a unique prey Mesodinium rubrum to perform its own photosynthesis, itself mixotrophic and feeds a cryptophyte, Teleaulax amphioxeia. The relationship between these three organisms is fundamental to understand the distribution and bloom dynamics of Dinophysis. In a first study, the effects of temperature, irradiance and pH on physiological aspects of T. amphioxeia were determined using a full factorial design before assessing the effect of contrasting physiological states after acclimation to two light intensities of T. amphioxeia and the effect of quantity of the prey for M. rubrum. The ecophysiological plasticity of T. amphioxeia suggests a high tolerance to future ocean conditions as well as the importance of prey abondance for growth of its predator. Subsequently, the effect of rapid salinity variations on D. sacculus were assessed, as such variations may be a potential driver of its distribution. D. sacculus present a large tolerance to salinity stresses, at least partly due to the synthesis of osmolytes, explaining its coastal disitrubution in areas subjected to rapid salinity fluctuations. Although toxicity and modes of actions of Dinophysis toxins are known on terrestrial mammals, the direct effects of Dinophysis and its toxins on marine organisms are still poorly studied. Thus, it was experimentally showed that Dinophysis and the pectenotoxin 2 (PTX2) impaired oyster oocytes, then affecting the fertilization rate, and causing damage to fish gills and mortality of larvae. Overall, this study highlights the importance of a better understanding of the physiology of the trophic chain of Dinophysis, and suggests negative effects of the dinoflagellate on aquatic ressources, which was unknown so far.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00666/77807/79981.pdf

https://archimer.ifremer.fr/doc/00666/77807/

Editor: | Université de Nantes
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

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