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| Registros recuperados: 31 | |
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| Thomas, Yoann; Garen, Pierre; Pouvreau, Stephane. |
| We applied, for the first time, a dynamic energy budget (DEB) growth model to the larval phase in the pearl oyster Pinctada margaritifera var. cumingii (Linnaeus, 1758) to evaluate the impact of spatio-temporal variation in the atoll lagoon environment on its capacity for development. The specific parameters of the model, which represent ingestion, temperature effect and the relationship between length and biovolume of the larvae, were determined from experiments or taken from the literature. The interpretation of the values of these parameters allowed us to identify the underlying adaptive character trait: P. margaritifera larvae have a good capacity to exploit low food concentrations and a narrow range of thermal tolerance restricted to hydrobiological... |
| Tipo: Text |
Palavras-chave: Growth Model; Dynamic Energy Budget; Larva; Pinctada Margaritifera; Atoll Lagoon. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00048/15919/13346.pdf |
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| Barillé, Laurent; Bris, Anthony Le; Goulletquer, Philippe; Thomas, Yoann; Glize, Philippe; Kane, Frank; Falconer, Lynne; Guillotreau, Patrice; Trouillet, Brice; Palmer, Stéphanie; Gernez, Pierre. |
| Oyster production has historically taken place in intertidal zones, and shellfish farms already occupy large extents of the French intertidal space. The expansion of French shellfish aquaculture within intertidal areas is therefore spatially limited, and moving production to the subtidal offshore environment is considered to be a possible solution to this problem. Finding new sites along the French Atlantic coast was studied here from the perspective of small oyster companies run by young farmers, who are interested in offshore bivalve aquaculture expansion compatible with their investment capacity. In assessing the feasibility of such offshore production, we considered three main issues: (1) bivalve growth potential and (2) technical feasibility and... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Site selection; Off-shore aquaculture; Remote sensing; Dynamic energy budget (DEB) model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00606/71819/70593.pdf |
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| Thomas, Yoann; Belliard, Corinne; Garen, Pierre; Gueguen, Yannick; Montagnani, Caroline. |
| In French Polynesia, the black-lip pearl oyster Pinctada margaritifera has been farmed to produce pearls since the 1980s, forming the basis of a major industry. The sustainability of this activity relies on spat collection in the lagoons. However, pearl oyster spat can be difficult to identify for the evaluation of stock variations. It is especially hard to distinguish Pinctada spp. larvae at a very early stage of development. In the present study, a whole- mount in situ hybridisation (ISH) technique was developed to allow the discrimination of larvae of closely-related pearl oyster species found in the French Polynesian atolls. Using specific ribosomal 16S-DNA sequence data, we were able to successfully differentiate between Pinctada margaritifera and... |
| Tipo: Text |
Palavras-chave: Whole larvae in situ hybridisation; 16S rRNA; Plankton; Species identification; Pearl oyster; Pinctada margaritifera. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14603/11923.pdf |
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| Huvet, Arnaud; Beguel, Jean-philippe; Pereira Cavaleiro, Nathalia; Thomas, Yoann; Quillien, Virgile; Boudry, Pierre; Alunno-bruscia, Marianne; Fabioux, Caroline. |
| Feeding strategies and digestive capacities can have important implications for variation in energetic pathways associated with ecological and economically important traits, such as growth or reproduction in bivalve species. Here, we investigated the role of amylase in the digestive processes of Crassostrea gigas, using in vivo RNA interference. This approach also allowed us to investigate the relationship between energy intake by feeding and gametogenesis in oysters. Double-stranded (ds)RNA designed to target the two α-amylase genes A and B was injected in vivo into the visceral mass of oysters at two doses. These treatments caused significant reductions in mean mRNA levels of the amylase genes: −50.7% and −59% mRNA A, and −71.9% and −70.6% mRNA B in 15... |
| Tipo: Text |
Palavras-chave: Alpha-Amylase; DsRNA; Gametogenesis; Marine bivalve; Dynamic energy budget. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00271/38239/36422.pdf |
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| Thomas, Yoann; Flye Sainte Marie, Jonathan; Chabot, Denis; Aguirre-velarde, Arturo; Marques, Gonçalo M; Pecquerie, Laure. |
| Hypoxia is a decrease in dissolved oxygen that causes physiological disturbances in marine fishes and invertebrates, including reduced mobility, growth rate and reproductive success, altered phenology and increased vulnerability to diseases. Under pressure from global changes such as warming or eutrophication, ocean and coastal ecosystems worldwide are becoming less oxygenated. In order to better understand the consequences of hypoxia on marine systems, there is a need for predicting hypoxia-induced changes from individual organisms to populations. By combining the effect of several stressors on species metabolic performances and life-history traits across their full life-cycle, the Dynamic Energy Budget (DEB) theory offers a suitable framework for... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00473/58466/65967.pdf |
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| Sangare, Nathanael; Lo-yat, Alain; Le Moullac, Gilles; Pecquerie, Laure; Thomas, Yoann; Beliaeff, Benoit; Andrefouet, Serge. |
| In French Polynesia black pearl farming represents one of the dominant business sectors. However, it still entirely relies on unpredictable Pinctada margaritifera spat collection success, which is itself conditioned by larval development completion. To assess the relationship between larval development and recruitment success, we studied under controlled conditions the effect of food concentration on development, growth, ingestion rate, survival and metabolic rate at the larval stage. Larvae were exposed to four different phytoplankton densities (2,5; 7,5; 15 and 30 cell.μL−1). Larvae survived equally all over the range of phytoplankton concentration with an average survival rate of 16% at the end of experiments. Food concentration significantly affected... |
| Tipo: Text |
Palavras-chave: Bivalve larvae; Pinctada margaritifera; Physiology; Energetics; Dynamic energy budget theory; Pearl farming; Aquaculture. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00476/58795/61446.pdf |
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| Thomas, Yoann; Pouvreau, Stephane; Alunno-bruscia, Marianne; Barille, Laurent; Gohin, Francis; Bryere, Philippe; Gernez, Pierre. |
| Aim The spread of non-indigenous species in marine ecosystems world-wide is one of today's most serious environmental concerns. Using mechanistic modelling, we investigated how global change relates to the invasion of European coasts by a non-native marine invertebrate, the Pacific oyster Crassostrea gigas. Location Bourgneuf Bay on the French Atlantic coast was considered as the northern boundary of C. gigas expansion at the time of its introduction to Europe in the 1970s. From this latitudinal reference, variations in the spatial distribution of the C. gigas reproductive niche were analysed along the north-western European coast from Gibraltar to Norway. Methods The effects of environmental variations on C. gigas physiology and phenology were studied... |
| Tipo: Text |
Palavras-chave: Biogeographical range expansion; Crassostrea gigas; DEB model; European coasts; Functional traits; Global change; Individual-based model; Invasive species; Remote-sensing. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00287/39828/38459.pdf |
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| Lemonnier, Hugues; Thomas, Yoann; Legrand, Alexandre; Martin, Jean-louis; Herbland, Alain. |
| In the booming context of shrimp culture in French Caledonia, some research actions need to be considered in order (i) to make sure this production will not impact the quality and biodiversity of the coastal environment it is contingent upon (ii) for the field to highlight, based on objective bases, its good "environmental image", for an efficient commercialization of its products. In the framework of the MOM project, a number of actions have been carried out: Action 1: A bibliographical synthesis of the impact of shrimp culture on coastal environment has been conducted, taking into account the works carried out throughout the world and in French Caledonia in order to draw the main issues the Territory will have to deal with. It seems necessary to start... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6593.pdf |
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| Sangare, Nathanael; Lo-yat, Alain; Le Moullac, Gilles; Pecquerie, Laure; Thomas, Yoann; Lefebvre, Sebastien; Le Gendre, Romain; Beliaeff, Benoit; Andréfouët, Serge. |
| The black-lipped pearl oyster (Pinctada margaritifera) is extensively farmed in French Polynesia to produce black pearls. For a sustainable management of marine resources, studying interactions between organisms and environment, and the associated factors and processes that will impact their life cycle and thus modulate population dynamics is a major research priority. Here, we describe black-lipped pearl oyster energy acquisition and use, and its control by temperature and food concentration within the Dynamic Energy Budget (DEB) theory framework. The model parametrization was based on literature data and a specific laboratory experiment. Model validation was carried out thanks to historical in-situ datasets and a dedicated field survey. Three theoretical... |
| Tipo: Text |
Palavras-chave: Bivalve; Physiology; Bioenergetics; Dynamic energy budget theory; Environmental change; Pearl farming. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72469/71614.pdf |
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| Thomas, Yoann; Dumas, Franck; Andrefouet, Serge. |
| The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia atoll lagoons. This aquaculture relies on spat collection, a process that experiences spatial and temporal variability and needs to be optimized by understanding which factors influence recruitment. Here, we investigate the sensitivity of P. margaritifera larval dispersal to both physical and biological factors in the lagoon of Ahe atoll. Coupling a validated 3D larval dispersal model, a bioenergetics larval growth model following the Dynamic Energy Budget (DEB) theory, and a population dynamics model, the variability of lagoon-scale connectivity patterns and recruitment potential is investigated. The relative contribution of... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Lagoon; Biophysical modelling; Connectivity; Population dynamics; DEB model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00321/43192/42926.pdf |
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| Thomas, Yoann; Dumas, Franck; Andrefouet, Serge. |
| Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors influence larval dispersal. Here, we investigate the sensitivity of P. margaritifera larval dispersal kernel to both physical and biological factors in the lagoon of Ahe atoll. Specifically, using a validated 3D larval dispersal model, the variability of lagoon-scale connectivity is investigated against wind forcing, depth and location of larval release, destination... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00197/30843/29210.pdf |
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| Fleury, Elodie; Barbier, Pierrick; Petton, Bruno; Normand, Julien; Thomas, Yoann; Pouvreau, Stephane; Daigle, Gaétan; Pernet, Fabrice. |
| Diseases pose an ongoing threat to aquaculture, fisheries and conservation of marine species, and determination of risk factors of disease is crucial for management. Our objective was to decipher the effects of host, pathogen and environmental factors on disease-induced mortality of Pacific oysters (Crassostrea gigas) across a latitudinal gradient. We deployed young and adult oysters at 13 sites in France and we monitored survival, pathogens and environmental parameters. The young oysters came from either the wild collection or the hatchery while the adults were from the wild only. We then used Cox regression models to investigate the effect of latitude, site, environmental factors and origin on mortality risk and to extrapolate this mortality risk to the... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73915/73251.pdf |
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| Pagano, Marc; Sagarra, Pascual-boi; Champalbert, Gisele; Bouvy, Marc; Dupuy, Christine; Thomas, Yoann; Charpy, Loic. |
| Metazooplankton abundance, biomass (<80 mu m, 200-500 mu m and >500 mu m) and community structure in the Ahe atoll were studied together with their relationships with environmental factors (temperature, salinity, wind) and trophic factors (phytoplankton, bacteria, heterotrophic nanoflagellates (HNF) and ciliates) during three periods in 2008-2009. Meroplankton, mainly bivalve and gastropod larvae, was dominant. Holoplankton was dominated by copepods, the main species being Oithona spp., Paracalanus parvus, Clausocalanus spp., Corycaeus spp., Acartia fossae and Undinula vulgaris. The results suggest a clear wind influence on the structure and horizontal distribution of the zooplankton communities. The metazooplankton appeared to be controlled mainly... |
| Tipo: Text |
Palavras-chave: Metazooplankton; Spatio-temporal patterns; Trophic relationships; Pearl oyster; Atoll lagoon; French Polynesia. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00101/21207/19419.pdf |
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| Gourault, Melaine; Petton, Sebastien; Thomas, Yoann; Pecquerie, Laure; Marques, Goncalo M.; Cassou, Christophe; Fleury, Elodie; Paulet, Yves-marie; Pouvreau, Stephane. |
| Identifying the drivers that control the reproductive success of a population is vital to forecasting the consequences of climate change in terms of distribution shift and population dynamics. In the present study, we aimed to improve our understanding of the environmental conditions that allowed the colonization of the Pacific oyster, Crassostrea gigas, in the Bay of Brest since its introduction in the 1960s. We also aimed to evaluate the potential consequences of future climate change on its reproductive success and further expansion. Three reproductive traits were defined to study the success of the reproduction: the spawning occurrence, synchronicity among individuals and individual fecundity. We simulated these traits by applying an individual-based... |
| Tipo: Text |
Palavras-chave: DEB model; IPCC scenarios; Reproductive traits; Crassostrea gigas; Bay of Brest. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00440/55188/56794.pdf |
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| Lavaud, Romain; Thomas, Yoann; Pecquerie, Laure; Benoit, Hugues P.; Guyondet, Thomas; Flye-sainte-marie, Jonathan; Chabot, Denis. |
| Like many marine species around the globe, several stocks of Atlantic cod (Gadus morhua) live in increasingly hypoxic waters. In the Gulf of Saint Lawrence (GSL) in Canada, the deep channels traversing the semi-enclosed sea exhibit year-round hypoxia, identified as one of the limiting factor for the recovery of GSL cod in its northern part. While many individuals in the northern GSL are known to venture in deeper, warmer, and more hypoxic waters of the Gulf channels, those in the southern GSL live in a shallower, colder, and more oxygenated environment. In this study, we use the modeling framework of the Dynamic Energy Budget (DEB) theory to disentangle the effects of hypoxia, temperature and food on the life-history traits of these two populations of cod... |
| Tipo: Text |
Palavras-chave: Hypoxia; Dynamic energy budget; Atlantic cod; Growth; Temperature; Gulf of Saint-Lawrence. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00448/55966/57472.pdf |
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| Pousse, Emilien; Flye-sainte-marie, Jonathan; Alunno-bruscia, Marianne; Hegaret, Helene; Rannou, Eric; Pecquerie, Laure; Marques, Goncalo M.; Thomas, Yoann; Castrec, Justine; Fabioux, Caroline; Long, Marc; Lassudrie, Malwenn; Hermabessiere, Ludovic; Amzil, Zouher; Soudant, Philippe; Jean, Fred. |
| As other filter-feeders, Crassostrea gigas can concentrate paralytic shellfish toxins (PST) by consuming dinoflagellate phytoplankton species like Alexandrium minutum. Intake of PST in oyster tissues mainly results from feeding processes, i.e. clearance rate, pre-ingestive sorting and ingestion that are directly influenced by environmental conditions (trophic sources, temperature). This study aimed to develop a mechanistic model coupling the kinetics of PST accumulation and bioenergetics in C. gigas based on Dynamic Energy Budget (DEB) theory. For the first time, the Synthesizing Units (SU) concept was applied to formalize the feeding preference of oysters between non-toxic and toxic microalgae. Toxin intake and accumulation were both dependent on the... |
| Tipo: Text |
Palavras-chave: Alexandrium minutum; Paralytic shellfish toxins (PST); Dynamic Energy Budget (DEB); Modelling; Pacific oyster. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00455/56662/58407.pdf |
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| Thomas, Yoann; Mazurie, Joseph; Alunno-bruscia, Marianne; Bacher, Cedric; Bouget, Jean-francois; Gohin, Francis; Pouvreau, Stephane; Struski, Caroline. |
| In order to assess the potential of various marine ecosystems for shellfish aquaculture and to evaluate their carrying capacities, there is a need to clarify the response of exploited species to environmental variations using robust ecophysiological models and available environmental data. For a large range of applications and comparison purposes, a non-specific approach based on ‘generic’ individual growth models offers many advantages. In this context, we simulated the response of blue mussel (Mytilus edulis L.) to the spatio-temporal fluctuations of the environment in Mont Saint-Michel Bay (North Brittany) by forcing a generic growth model based on Dynamic Energy Budgets with satellite-derived environmental data (i.e. temperature and food). After a... |
| Tipo: Text |
Palavras-chave: Mussel; DEB; SeaWifs; Aquaculture; Site Selection; Resource Management. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00037/14836/14537.pdf |
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| Registros recuperados: 31 | |
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