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| Horri, Khaled; Alfonso, Sebastien; Cousin, Xavier; Munschy, Catherine; Loizeau, Veronique; Aroua, Salima; Begout, Marie-laure; Ernande, Bruno. |
| Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants that have been shown to affect fish life-history traits such as reproductive success, growth and survival. At the individual level, their toxicity and underlying mechanisms of action have been studied through experimental exposure. However, the number of experimental studies approaching marine environmental situations is scarce, i.e., in most cases, individuals are exposed to either single congeners, or single types of molecules, or high concentrations, so that results can hardly be transposed to natural populations. In the present study, we evaluated the effect of chronic dietary exposure to an environmentally realistic marine mixture of PCB and... |
| Tipo: Text |
Palavras-chave: Contaminants; Body length; Condition; Fertilization rate; Energy allocation; Trade-off. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00396/50694/51450.pdf |
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| Alfonso, Sebastien. |
| In the frame of this thesis, we first studied the establishment of personality in teleost, the consistency across context and different life stages as well as the associated physiological mechanisms. Personality appeared consistent across contexts over a short time period but it was no longer the case over a long period of time, especially between different life stages. Physiological mechanisms of stress regulation, as well as activity and neural plasticity, differed according to individual boldness. Then, we studied the physiological and behavioural responses of teleost fish chronically exposed to an environmentally relevant mixture of POP (PCBs and PBDEs), as well as those of their unexposed offspring. Different behavioural alterations in larval... |
| Tipo: Text |
Palavras-chave: Polluants; Comportement; Environnement; Stress; Polluants; Stress; Teleost fish; Environment. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00499/61019/64421.pdf |
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| Geoffroy, Benjamain; Alfonso, Sebastien; Sadoul, Bastien; Blumstein, Daniel T. |
| Humans currently occupy all continents and by doing so, modify the environment and create novel threats to many species; a phenomenon known as human-induced rapid environmental changes (HIREC). These growing anthropogenic disturbances represent major and relatively new environmental challenges for many animals, and invariably alter selection on traits adapted to previous environments. Those species that survive often have moved from their original habitat or modified their phenotype through plasticity or genetic evolution. Based on the most recent advances in this research area, we predict that wild individuals with highly plastic capacities, relatively high basal stress level, and that are generally shy—in other words, individuals displaying a reactive... |
| Tipo: Text |
Palavras-chave: Coping style; Antipredator behavior; Evolution; Stress physiology; Ecology; Predation; Urbanization; Pollution. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00664/77564/79528.pdf |
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| Alfonso, Sebastien; Sadoul, Bastien; Cousin, Xavier; Bégout, Marie-laure. |
| In aquaculture, fish are exposed to unavoidable stressors that can be detrimental for their health and welfare. However, welfare in farmed fish can be difficult to assess, and, so far, no standardized test has been universally accepted as a welfare indicator. This work contributes to the establishment of behavioural welfare indicators in a marine teleost in response to different water quality acute stressors. Groups of ten fish were exposed to high Total Ammonia Nitrogen concentration (High TAN, 18 mg.L-1), Hyperoxia (200 % O2 saturation), Hypoxia (20 % O2 saturation), or control water quality (100% O2 saturation and TAN < 2.5 mg.L-1) over 1 hour. Fish were then transferred in a novel environment for a group behaviour test under the same water quality... |
| Tipo: Text |
Palavras-chave: Fish; Welfare; Water quality; Behaviour; Stress. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72399/71344.pdf |
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| Sadoul, Bastien; Blumstein, Daniel T.; Alfonso, Sebastien; Geffroy, Benjamin. |
| Wild animals face novel environmental threats from human activities that may occur along a gradient of interactions with humans. Recent work has shown that merely living close to humans has major implications for a variety of antipredator traits and physiological responses. Here, we hypothesize that when human presence protects prey from their genuine predators (as sometimes seen in urban areas and at some tourist sites), this predator shield, followed by a process of habituation to humans, decouples commonly associated traits related to coping styles, which results in a new range of phenotypes. Such individuals are characterized by low aggressiveness and physiological stress responses, but have enhanced behavioral plasticity, boldness, and cognitive... |
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| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/80053/83056.pdf |
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| Blanc, Mélanie; Alfonso, Sebastien; Bégout, Marie-laure; Barrachina, Célia; Hyötyläinen, Tuulia; Keiter, Steffen H.; Cousin, Xavier. |
| Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants still present in aquatic environments despite their total or partial ban. Previously, we observed that an environmentally realistic mixture of these compounds affects energy balance, growth, and reproduction in exposed zebrafish (F0), and behavior in their unexposed offspring (F1-F4). In the present work, we performed lipidomic and transcriptomic analyses on brains of zebrafish (F0-F2) from exposed and control lineages to identify molecular changes that could explain the observed phenotypes. The use of both technologies highlighted that F0 zebrafish displayed impaired mitochondrial function and lipid metabolism regulation (depletion in... |
| Tipo: Text |
Palavras-chave: Danio rerio; Persistent-organic pollutant; Neurotoxicity; Brain metabolism; RNA-Seq. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00646/75797/76720.pdf |
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| Alfonso, Sebastien; Peyrafort, Manon; Cousin, Xavier; Bégout, Marie-laure. |
| Coping style is defined as a set of individual physiological and behavioural characteristics consistent across time and context. In the zebrafish Danio rerio, as well as in many other animals, several covariations have been established between behavioural, physiological, and molecular responses. However, not many studies have addressed the consistency of behavioural responses over time starting at the larval stage. Therefore, we aimed to improve our understanding of behavioural consistency across context and over time in zebrafish from the larval to juvenile stages. We conducted two distinct experiments: a larval stage experiment (from 8 to 21 days post fertilization, dpf) and a juvenile stage experiment (from 21 to 60 dpf). On one hand, the larval... |
| Tipo: Text |
Palavras-chave: Coping style; Fish; Personality; Vital staining. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72598/71598.pdf |
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| Sadoul, Bastien; Alfonso, Sebastien; Bessa, E.; Bouchareb, A.; Blondeau-bidet, E.; Clair, P.; Chatain, Beatrice; Begout, Marie-laure; Geffroy, Benjamin. |
| Stress enhances or inhibits neurogenesis in mammals and some fish species. The link between the two processes is still unclear. Most studies have been performed in very specific stressful or altered environments. Despite the known inter-individual divergence in coping abilities within populations, the relationship between the stress axis and neurogenesis has never been addressed in unstressed individuals. Here we correlate brain expression of the pcna (proliferating cell nuclear antigen) and neurod1 (neurogenic differentiation factor 1) genes, two markers of neurogenesis, with transcripts of cortisol receptors in three fish species living in very distinct environments. Within the three species, individuals with the highest expression of neurogenesis genes... |
| Tipo: Text |
Palavras-chave: Neurogenesis; Stress; Glucocorticoid receptor; Mineralocorticoid receptor; Hypothalamo-pituitary-interrenal axis. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00444/55560/57164.pdf |
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| Alfonso, Sebastien; Sadoul, Bastien; Gesto, Manuel; Joassard, Lucette; Chatain, Beatrice; Geffroy, Benjamin; Bégout, Marie-laure. |
| Coping styles consist of a coherent set of individual physiological and behavioral differences in stress responses that are consistent across time and context. Such consistent inter-individual differences in behavior have already been shown in European sea bass (Dicentrarchus labrax), but the associated mechanisms are still poorly understood. Here, we combine physiological measurements with individual behavioral responses in order to characterize coping styles in fish. Fish were tagged and placed in a tank for group risk-taking tests (GRT) at 8 months of age to evaluate boldness using the proxy latency of leaving a sheltered area towards an open area. A subsample of these fish were individually challenged 16 months later using an open field test (OFT), in... |
| Tipo: Text |
Palavras-chave: Personality; HPI axis; Gene transcription; Neurotransmitters. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00491/60282/63708.pdf |
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