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| Registros recuperados: 50 | |
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| Payan, P; Borelli, G; Priouzeau, F; De Pontual, Helene; Boeuf, G; Mayer Gostan, N. |
| Kinetic and pharmacological characteristics of Ca2+ fluxes across the saccular epithelium of trout were studied using a perfused isolated inner ear. Ca-45(2+) influx from the Ringer solution to the endolymph was 3-4 nmoles h(-1) mu(-1) endolymph, which corresponds to a global turnover rate of the endolymph calcium of 200% h(-1). Ca2+ entry into the proximal endolymph was faster than into the distal fluid. Net Ca2+ movement across the saccular epithelium depended on the direction and intensity of the chemical gradient of calcium between the Ringer solution and the endolymph. Increasing the calcium concentration in the Ringer solution up to 4.4 mmol l(-1) provoked an accumulation of Ca2+ in both proximal and distal endolymphs, and equilibrium was reached... |
| Tipo: Text |
Palavras-chave: Inner ear; Perfusion; Otolith; Endolymph; Flux; Calcium; Oncorhynchus mykiss; Trout. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-416.pdf |
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| Fablet, Ronan; Chessel, Anatole; Carbini, Sebastien; Benzinou, Abdesslam; De Pontual, Helene. |
| In this paper is presented a novel image processing tool for the extraction of geometric information in otolith images. It relies on the reconstruction of individual otolith shape histories from otolith images. Based on the proposed non-parametric level-set representation of otolith shape history, applications to the extraction of growth axes and ring structures in otolith images are first considered. A second category of applications concern the analysis of 2D otolith growth. The potential of the proposed framework is illustrated on real otolith images for various species (e.g., cod, pollock) and discussed with a particular emphasis on the genericity of the approach and on applications such as otolith shape analysis, multi-proxy otolith analysis, otolith... |
| Tipo: Text |
Palavras-chave: 2D otolith growth; Growth axis extraction; Growth ring extraction; Shape dynamics; Otolith imaging. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6319.pdf |
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| Mellon-duval, Capucine; De Pontual, Helene; Metral, Luisa; Quemener, Loic. |
| Growth of European hake was estimated from the results of a conventional tagging study in the Gulf of Lions, the first tagging experiment to have been undertaken on the species in Mediterranean waters. In all, 4277 hake 15–40 cm long were tagged and released on the inshore fishing grounds during spring 2006. The overall recapture rate was 6.5% and times-at-liberty ranged from 1 to 717 d. Growth rate in hake varied with size and sex. The estimated growth parameter (von Bertalanffy k) was estimated as double previously published values based on size frequency distribution in the area. Compared with recent growth parameters derived from the tagging experiments in the Bay of Biscay, k was estimated to be slightly lower in the Gulf of Lions. With this faster... |
| Tipo: Text |
Palavras-chave: Age estimation; European hake; Growth; Mediterranean; Tagging. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00000/11134/11532.pdf |
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| Woillez, Mathieu; Fablet, Ronan; Tran-thanh Ngo,; Lalire, Maxime; Lazure, Pascal; De Pontual, Helene. |
| Numerous methods have been developed to geolocate fish from data storage tags. Whereas demersal species have been tracked using tide-driven geolocation models, pelagic species which undertake extensive migrations have been mainly tracked using light-based models. Here, we present a new HMM-based model that infers pelagic fish positions from the sole use of high-resolution temperature and depth histories. A key contribution of our framework lies in model parameter inference (diffusion coefficient and noise parameters with respect to the reference geophysical fields—satellite SST and temperatures derived from the MARS3D hydrodynamic model), which improves model robustness. As a case study, we consider long time series of data storage tags (DSTs) deployed on... |
| Tipo: Text |
Palavras-chave: Fish movement; Archival tagging; Migration; Population structure; Hidden Markov Model (HMM); State-space model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00300/41097/40270.pdf |
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| Edeyer, Anaick; De Pontual, Helene; Payan, P; Troadec, Herve; Severe, Armelle; Mayer-gostan, N. |
| We studied the circadian variations of the ionic composition ([Na+], [K+], [Cl-]), total CO2 ([tot CO2]), and protein concentration ([protein]) in the plasma and endolymph in the distal and proximal sides of the sacculus in the turbot Psetta maxima. Daily variations in total plasma calcium ([tot Ga]) were also recorded. Significant diurnal fluctuations occurred in most parameters and the spatial heterogeneity of the endolymph composition was maintained throughout a 24 h period. The main parameters implicated in otolith calcification, endolymph [tot CO2] and endolymph [protein], fluctuated diurnally, [tot CO2] was highest and [protein] lowest at night; the relative concentrations were reversed during the day. The inverse, alternating relationship of maximal... |
| Tipo: Text |
Palavras-chave: Daily cycle; Endolymph; Otolith; Chemical composition; Teleost. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10572/7603.pdf |
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| Lopez, Romain; De Pontual, Helene; Bertignac, Michel; Mahevas, Stephanie. |
| European sea bass, Dicentrarchus labrax, is a highly valuable species in Europe, both for aquaculture in the Mediterranean Sea and for commercial and recreational fisheries in the North East Atlantic Ocean. Subjected to increasing fishing pressure, the wild population has recently experienced significant recruitment fluctuation as well as a northward extension of its distribution area in the North Sea. While the nature of the ecological and/or physiological processes involved remains unresolved, ontogenetic habitat shifts and adult site fidelity could increase the species’ vulnerability to climate change and overfishing. As managers look for expert information to propose management scenarios leading to sustainable exploitation, exploratory modelling... |
| Tipo: Text |
Palavras-chave: Population dynamics; Essential habitats; Connectivity; Bioenergetic modeling; Phenotypic plasticity; Life cycle adaptation. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00341/45258/44699.pdf |
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| Pineiro, C; Rey, J; De Pontual, Helene; Garcia, A. |
| Daily growth of Atlantic juvenile hake from Northwest Iberia has been estimated employing a new approach combining analyses of transversal and sagittal sections of the otoliths along the ventral radius. Age of juvenile hake ranging from 3 to 25 cm collected during a spring 2002 survey was estimated. Somatic growth followed a power fit: Fish size (TL) = 3.3254*age(0.7336) (r(2) =0.87, p < 0.001, n = 76). yielding an average individual growth rate of 0.66 mm/day (0.06). The growth model indicates that after a year's life a juvenile can reach 25 cm. Otolith ventral radius ranged from 401 to 1842 mu m and daily increments were between 104 and 387. Fish growth and otolith growth were closely related (r(2) = 0.92 p < 0.001, n = 76). These first results of... |
| Tipo: Text |
Palavras-chave: NW Iberian waters; Seasonal variation; Daily growth; Otolith microstructure; Juvenile hake. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6111.pdf |
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| Fave, Sébastien; Crepin, Emeline; Magalhaes, José Ramos; Ogor, Andre; De Pontual, Helene; Mahe, Kelig. |
| Chaque année, près d’1 million de pièces calcifiées (dont 35 000 en France) sont analysées pour l’évaluation de l’état des ressources marines. De plus, beaucoup de thématiques de recherche nécessitent elles-aussi l’utilisation de ces pièces calcifiées. Ainsi, depuis plus de 20 ans, un partenariat entre la société VSG (Visualization Sciences Group anciennement Noesis) et l’institut de recherche IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer) a permis de développer le logiciel d'analyse d'images dédié aux pièces calcifiées, nommé TNPC (Traitement Numérique des Pièces Calcifiées, www.tnpc.fr). Divers projets de recherche et collaborations en particulier avec l’ENIB (Ecole Nationale des Ingénieurs de Brest) ont été nécessaires pour... |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00148/25905/23922.pdf |
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| Dambrine, Chloe; Huret, Martin; Woillez, Mathieu; Pecquerie, Laure; Allal, Francois; Servili, Arianna; De Pontual, Helene. |
| The European seabass (Dicentrarchus labrax) is a species of particular ecological and economic importance. Stock assessments have recently revealed the worrying state of the “Northern stock”, probably due to overfishing and a series of poor recruitments. The extent to which these poor recruitments are due to environmental variability is difficult to assess, as the processes driving the seabass life cycle are poorly known. Here we investigate how food availability and temperature may affect the growth and survival of wild seabass at the individual scale. To this end, we developed a bioenergetics model based on the Dynamic Energy Budget (DEB) theory. We applied it to seabass population of the Northeast Atlantic region (Bay of Biscay – English Channel area)... |
| Tipo: Text |
Palavras-chave: Dicentrarchus labrax Northeast Atlantic Dynamic Energy Budget theory Growth; Starvation Early-life stages. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72397/71341.pdf |
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| Heral, Maurice; Bacher, Cedric; Razet, Daniel; Prou, Jean; Deslous-paoli, Jean-marc; De Pontual, Helene; Raillard, Olivier; Maestrini, Serge; Mornet, Francoise; Menesguen, Alain; Sautour, Benoit; Robert, Jean-michel. |
| Les termes du contrat passé entre le Fond de la Recherche et de la Technologie et l'IFREMER précisent qu ele programmer a pour objectif une gestion rationnelle du milieu conchylicole avec notamment une mise au point de modèles (voir notification de l'aide en annexe). Un premier modèle appelé modèle global par analogie avec les modèles de pêche met en évidence la limite de la capacité trophique du bassin de Marennes-Oléron pour les huîtres cultivées. Un modèle analytique avec un modèle physique simple permet dans un premier temps de développer un modèle de croissance des huîtres en fonction de la nourriture disponible et d'effectuer des simulations qui confirment l'influence du stock sur les performances de croissance des bivalves. Un troisième approche... |
| Tipo: Text |
Palavras-chave: Modèle production; Biomasse; Huître creuse; Crassostrea gigas; Modèle énergétique; Croissance; Modèle multiboîte; Marennes Oléron; Modèle trophique; Marennes Oléron. |
| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00048/15908/13337.pdf |
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| Le Goff, Ronan; Drogou, Mickael; De Pontual, Helene; Talidec, Catherine; Berthou, Patrick; Biseau, Alain. |
| Une réunion technique a été organisée le 21 mai 2013 par la Commission européenne afin de faire le point sur l’état du stock de bar commun (Dicentrarchus labrax) dans les eaux européennes de l’Atlantique du Nord Est. Cette réunion a conclu que le stock de bar peut être considéré comme dans un état « alarmant », et la Commission a demandé aux Etats membres d’identifier les mesures de gestion qu’ils seraient à même de mettre en place dans les meilleurs délais pour obtenir une diminution des captures de 20%. C’est dans ce contexte que la DPMA a adressé à l’Ifremer la présente saisine, en attendant plus particulièrement de l’Institut : - de lister les mesures concrètes applicables aux pêcheries françaises et permettant de réduire les captures et donc la... |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00165/27657/25827.pdf |
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| Dambrine, Chloe; Woillez, Mathieu; Huret, Martin; De Pontual, Helene. |
| Fish habitats sustain essential functions for fish to complete their life cycle, such as feeding, growing and spawning. Conservation is crucial to maintain fish populations and their exploitation. Since 2013, the spawning stock biomass of the northern stock of European seabass (Dicentrarchus labrax) has been in a worrying state. A series of low recruitments with a persistently high level of fishing has been blamed, raising concerns about the processes involved in seabass reproduction and settlement in nurseries. Here, we characterise seabass spawning areas along the French Atlantic coast using vessel monitoring system (VMS) data. A non‐linear geostatistical approach was applied, from 2008 to 2014, to detect locations where seabass aggregate for spawning.... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Bayesian spatio‐temporal modelling; Dicentrarchus labrax; English Channel; European sea bass; Non‐linear geostatistics; Spawning grounds. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00668/77997/80218.pdf |
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| Panfili, Jacques; De Pontual, Helene; Troadec, Herve; Wrigh, Peter J.. |
| Sclerochronology, the study of calcified structures to reconstruct the past history of living organisms, is central to fish biology and fisheries management. This manual aims to provide an overview of the current theoretical and practical aspects of sclerochronological studies. By providing information on the nature of calcified structures (otoliths, scales, skeleton), their uses in fish research and methods for preparation and examination, the manual constitutes a comprehensive guide for researchers, technicians and students either new to the field or interested in expanding their range of expertise. The enclosed multimedia version (DVD) is supplemented by videos illustrating the main technical procedures with an alternative navigation mode based on... |
| Tipo: Text |
Palavras-chave: Age; Age determination; Biological aging; Chemistry; Growth; Otolith reading; Otoliths; Scale reading; Scales; Skeleton. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00017/12801/9742.pdf |
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| Baglinière, J. L.; Bomassi, P.; Bousquet, B.; Chancerel, F.; De Pontual, Helene; Dumas, J.; Euzenat, G.; Fontenelle, G.; Fournel, F.; Gayou, F.; Luquet, J. F.; Maisse, G.; Martin Ventura, J. A.; Marty, A.; Nihouarn, A.; Porcher, J. P.; Prevost, E.; Prouzet, Patrick; Pustelnik, G.; Richard, A.; Troadec, Herve. |
| This report confirms interpretation criteria used in scale reading for age determination of Atlantic Salmon in freshwater and in sea water with typical examples. The difficulties for age determination of wild and reared populations by showing atypical examples are presented. Finally some recommandations to a better knowledge of Atlantic salmon population in south distribution area are proposed. |
| Tipo: Text |
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| Ano: 1985 |
URL: https://archimer.ifremer.fr/doc/00480/59127/61755.pdf |
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| Mahé, Kelig; Gourtay, Clemence; Bled--defruit, Geoffrey; Chantre, Celina; De Pontual, Helene; Amara, Rachid; Claireaux, Guy; Audet, C.; Zambonino-infante, Jose-luis; Ernande, Bruno. |
| Otolith shape is an efficient tool for fish stock discrimination. Therefore, it is crucial to identify the environmental parameters that could influence otolith morphogenesis and growth. Current global ocean warming negatively affects the production of polyunsaturated fatty acids (EPA and DHA) by phytoplankton and thus their availability in marine food webs. As EPA and DHA are essential nutrients for most fish species, their deficiency could affect many aspects of fish physiology, notably otolith morphogenesis. The goal of this study was to assess experimentally the combined influences of temperature (T) and dietary polyunsaturated fatty acid (PUFA) content on European seabass (Dicentrarchus labrax) otolith morphogenesis during early life stages. 300... |
| Tipo: Text |
Palavras-chave: N-3 polyunsaturated fatty acids; Otolith shape; Temperature effect; Elliptic Fourier descriptors; Multivariate mixed-effects models; Directional asymmetry. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70054/68017.pdf |
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| Registros recuperados: 50 | |
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