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| Registros recuperados: 12 | |
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| Geffroy, Benjamin; Sadoul, Bastien; Putman, Breanna J.; Berger-tal, Oded; Garamszegi, László Zsolt; Møller, Anders Pape; Blumstein, Daniel T.; De Waal, Frans B. M.. |
| Humans profoundly impact landscapes, ecosystems, and animal behavior. In many cases, animals living near humans become tolerant of them and reduce antipredator responses. Yet, we still lack an understanding of the underlying evolutionary dynamics behind these shifts in traits that affect animal survival. Here, we used a phylogenetic meta-analysis to determine how the mean and variability in antipredator responses change as a function of the number of generations spent in contact with humans under 3 different contexts: urbanization, captivity, and domestication. We found that any contact with humans leads to a rapid reduction in mean antipredator responses as expected. Notably, the variance among individuals over time observed a short-term increase followed... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76397/77422.pdf |
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| Geffroy, Benjamin; Douhard, Mathieu. |
| The impact of early stress on juvenile development has intrigued scientists for decades, but the adaptive significance of such effects remains an ongoing debate. This debate has largely ignored some characteristics of the offspring, such as their sex, despite strong evolutionary and demographic implications of sex-ratio variation. We review recent studies that examine associations between glucocorticoids (GCs), the main class of stress hormones, and offspring sex. Whereas exposure to GCs at around the time of sex determination in fish consistently produces males, the extent and direction of sex-ratio bias in response to stress vary in reptiles, birds, and mammals. We propose proximate and ultimate explanations for most of these trends. |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00487/59858/63141.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... |
| Tipo: Text |
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| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/80053/83056.pdf |
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| Vandeputte, Marc; Clota, Frederic; Sadoul, Bastien; Blanc, Marie-odile; Blondeau-bidet, Eva; Bégout, Marie-laure; Cousin, Xavier; Geffroy, Benjamin. |
| Temperature‐dependent sex determination (TSD) can be observed in multiple reptile and fish species. It is adaptive when varying environmental conditions advantage either males or females. A good knowledge of the thermosensitive period is key to understand how environmental changes may lead to changes in population sex ratio. Here, by manipulating temperature during development, we confirm that cold temperature (16°C) increases the proportion of fish that develop as females in European sea bass (Dicentrarchus labrax) until 56 days posthatching, but show that it has an opposite effect at later stages, with the proportion of males reaching ~90% after 230 days at 16°C. This is the first observation of opposite effects of temperature at different time periods... |
| Tipo: Text |
Palavras-chave: Dicentrarchus labrax; Fish; Sex ratio; Temperature-dependent sex determination; Thermosensitive period; TSD. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/76965/78184.pdf |
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| Sadoul, Bastien; Geffroy, Benjamin. |
| Stress in teleosts is an increasingly studied topic because of its interaction with growth, reproduction, immune system and ultimately fitness of the animal. Whether it is for evaluating welfare in aquaculture, adaptive capacities in fish ecology, or to investigate effects of human‐induced rapid environmental change, new experimental methods to describe stress physiology in captive or wild fish have flourished. Cortisol has proven to be a reliable indicator of stress and is considered the major stress hormone. Initially principally measured in blood, cortisol measurement methods are now evolving towards lower invasiveness and to allow repeated measurements over time. We present an overview of recent achievements in the field of cortisol measurement in... |
| Tipo: Text |
Palavras-chave: Aquaculture; Cortisol; Glucocorticoids; Non-invasive; Stress; Welfare. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00478/59001/61616.pdf |
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| Geffroy, Benjamin; Sadoul, Bastien; Bouchareb, Amine; Prigent, Sylvain; Bourdineaud, Jean-paul; Gonzalez-rey, Maria; Morais, Rosana N.; Mela, Maritana; Carvalho, Lucelia Nobre; Bessa, Eduardo. |
| Nature-based tourism is gaining extensive popularity, increasing the intensity and frequency of human-wildlife contacts. As a consequence, behavioral and physiological alterations were observed in most exposed animals. However, while the majority of these studies investigated the effects of punctual exposure to tourists, the consequences of constant exposition to humans in the wild remains overlooked. This is an important gap considering the exponential interest for recreational outdoor activities. To infer long-term effects of intensive tourism, we capitalized on Odontostilbe pequira, a short-lived sedentary Tetra fish who spends its life close to humans, on which it feeds on dead skin. Hence, those fish are constantly exposed to tourists throughout their... |
| Tipo: Text |
Palavras-chave: Coping style; Ecotourism; Conservation; Behavior; Gene expression; Cortisol; Neurogenesis; Fish. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00423/53470/54366.pdf |
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| Samia, Diogo S. M.; Bessa, Eduardo; Blumstein, Daniel T.; Nunes, José A. C. C.; Azzurro, Ernesto; Morroni, Lorenzo; Sbragaglia, Valerio; Januchowski‐hartley, Fraser A.; Geffroy, Benjamin. |
| In an increasingly anthropic world, humans have profound impacts on the distribution and behaviour of marine fishes. The increased human presence has modified fishesf antipredator behavioural responses, and consequently flight decisions, as a function of their changed perceptions of risk. Understanding how fish react to human presence can help identify the most vulnerable functional groups/species and estimate impacts caused by human disturbance. Shoal and body size are known to influence fish flight initiation distance (FID; the distance between the predator and prey when the prey begins to escape); however, few studies attempt to test the moderators of these relationships. Here, we present a comprehensive meta]analysis evaluating FID of fish in... |
| Tipo: Text |
Palavras-chave: Antipredator behaviour; Economic escape theory; Fish size; Flight initiation distance; Shoal size. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00500/61173/64775.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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| Mallet, Alicia; Jouvenel, Jean-yves; Broyon, Morgane; Pirot, Nelly; Geffroy, Benjamin. |
| The mutable nassa, Tritia mutabilis, a marine gastropod that is widely exploited on the Adriatic coast is an important source of income for small-scale fishermen in the Mediterranean Sea, particularly in the Gulf of Lion. However, the lack of knowledge on the ecology and biology of this species limits our capacities to propose and produce an effective management plan. As a result, stocks are currently declining, especially in Italy. In order to optimize a management plan for this fishery, we designed a study to better characterize the reproductive biology of T. mutabilis, using gonad histology and performing a regular monitoring of population size frequency. The average shell height of individuals during the breeding period was 24 ± 2.7mm for males and 30... |
| Tipo: Text |
Palavras-chave: Tritia mutabilis; Gonad histology; Gonochoric species; Size at first maturity; Fisheries management. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00686/79831/82637.pdf |
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| Registros recuperados: 12 | |
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