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Auteur Hauser, M.; Duponchelle, F.; Hermann, T.W.; Limburg, K.E.; Castello, L.; Stewart, D.J.; Torrente-Vilara, G.; Garcia-Vasquez, A.; Garcia-Davila, C.; Pouilly, M.; Pecheyran, C.; Ponzevera, E.; Renno, J.-F.; Moret, A.S.; Doria, C.R.C. doi  openurl
  Titre Unmasking continental natal homing in goliath catfish from the upper Amazon Type Article scientifique
  Année 2020 Publication Revue Abrégée Freshw. Biol.  
  Volume 65 Numéro 2 Pages 325-336  
  Mots-Clés Brachyplatystoma rousseauxii; brachyplatystoma-rousseauxii; dam impacts; fish; fresh-water; hydropower; microchemistry; migration; otolith; otolith chemistry; pacific salmon; philopatry; river; strontium  
  Résumé Amazonian goliath catfishes are widespread in the Amazon Basin. Recently, otolith Sr-87:Sr-86 analyses using laser ablation-multi-collector-inductively coupled plasma mass spectrometry (LA-MC-ICPMS) revealed a >8,000 km trans-Amazonian natal homing in Brachyplatystoma rousseauxii among fish caught and hatched in the largest Amazon River tributary, the upper Madeira basin. Although also suspected for fish in the upper Amazon, homing could not be demonstrated owing to less distinct environmental Sr-87:Sr-86 gradients along the Amazon mainstem. Using scanning X-ray fluorescence microscopy (SXFM), a separate study provided evidence that Se:Ca and Sr:Ca are useful markers for identifying migration into Andean headwaters and the estuarine environment. We analysed otoliths of known Sr-87:Sr-86 profiles using SXFM mapping to test if Sr:Ca and Se:Ca patterns could demonstrate natal homing for three fish caught in the upper Amazon, using as reference two individuals that were natal homers and two forced residents (hatched after the construction of hydroelectric dams on the Madeira River) from the upper Madeira River. As hypothesised, although the Sr isotope profiles of the upper Amazon individuals were uninformative, two of them presented similar alternating mirror patterns of Sr:Ca and Se:Ca to those of the upper Madeira natal homers, indicating migrations out of the Andean region and into the estuary area. Both were therefore natal homers from the upper Amazon. The third individual from the upper Amazon presented similar Sr:Ca and Se:Ca patterns to those of the upper Madeira residents, suggesting it was a natural resident from the upper Amazon. By combining the results of Sr-87:Sr-86 analyses (LA-MC-ICPMS) and Sr:Ca and Se:Ca mappings (SXFM) that are completely independent of one another, we demonstrated that B. rousseauxii also performs natal homing in the upper Amazon. Our results indicate that the life cycle of B. rousseauxii is more complex than previous literature hypothesised, with the existence of partial migration, even in absence of physical barriers. Quantifying the relative importance of these different life-history strategies will have important implications for fisheries management. Our results also lay the groundwork for conservation efforts in the context of hydropower development in the Amazon Basin and set testable hypotheses of the potential impacts of the Madeira River dams.  
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  ISSN 0046-5070 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2703  
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Auteur Ben Othman, H.; Leboulanger, C.; Le Floc'h, E.; Mabrouk, H.H.; Hlaili, A.S. url  doi
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  Titre Toxicity of benz(a)anthracene and fluoranthene to marine phytoplankton in culture: Does cell size really matter? Type Article scientifique
  Année 2012 Publication Revue Abrégée J. Hazard. Mater.  
  Volume 243 Numéro Pages 204-211  
  Mots-Clés Benz(a)anthracene; Ecotoxicity; Fluoranthene; Size-sensitivity relationship; aquatic organisms; biodegradation; chlorophyll; fluorescence; food-web; fresh-water phytoplankton; in-vitro; organic pollutants; pahs; phytoplankton; polycyclic aromatic-hydrocarbons; surface sediments  
  Résumé The toxicity of benz(a)anthracene and fluoranthene (polycyclic aromatic hydrocarbons, PAHs) was evaluated on seven species of marine algae in culture belonging to pico-, nano-, and microphytoplankton, exposed to increasing concentrations of up to 2 mg L-1. The short-term (24 h) toxicity was assessed using chlorophyll a fluorescence transients, linked to photosynthetic parameters. The maximum quantum yield Fv/Fm was lower at the highest concentrations tested and the toxicity thresholds were species-dependent. For acute effects, fluoranthene was more toxic than benz(a)anthracene, with LOECs of 50.6 and 186 mu g L-1, respectively. After 72 h exposure, there was a dose-dependent decrease in cell density, fluoranthene being more toxic than benz(a)anthracene. The population endpoint at 72 h was affected to a greater extent than the photosynthetic endpoint at 24 h. EC50 was evaluated using the Hill model, and species sensitivity was negatively correlated to cell biovolume. The largest species tested, the dinoflagellate Alexandrium catenella, was almost insensitive to either PAH. The population endpoint EC50s for fluoranthene varied from 54 mu g L-1 for the picophytoplankton Picochlorum sp. to 418 mu g L-1 for the larger diatom Chaetoceros muelleri. The size/sensitivity relationship is proposed as a useful model when there is a lack of ecotoxicological data on hazardous chemicals, especially in marine microorganisms. (C) 2012 Elsevier B.V. All rights reserved.  
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  ISSN 0304-3894 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 915  
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Auteur Villeger, S.; Brosse, S.; Mouchet, M.; Mouillot, D.; Vanni, M.J. doi  openurl
  Titre Functional ecology of fish: current approaches and future challenges Type Article scientifique
  Année 2017 Publication Revue Abrégée Aquat. Sci.  
  Volume 79 Numéro 4 Pages 783-801  
  Mots-Clés biodiversity; centrarchid fishes; coral-reef fishes; dietary-morphological relationships; ecosystem processes; Ecosystem services; fish; food-web; fresh-water fish; functional trait; global change; labrid fishes; life-history strategies; ocean; phosphorus-limitation; population regulation; river  
  Résumé Fish communities face increasing anthropogenic pressures in freshwater and marine ecosystems that modify their biodiversity and threaten the services they supply to human populations. To address these issues, studies have been increasingly focusing on functions of fish that are linked to their main ecological roles in aquatic ecosystems. Fish are indeed known to control other organisms through predation, mediate nutrient fluxes, and can act as ecosystem engineers. Here for each of the key functions played by fish, we present the functional traits that have already been used to assess them. We include traits measurable from observations on living individuals, morphological features measured on preserved organisms or traits categorized using information from the literature, and we discuss their respective advantages and limitations. We then list future research directions to foster a more complete functional approach for fish ecology that needs to incorporate functional traits describing, food provisioning and cultural services while accounting more frequently for intraspecific variability. Finally, we highlight ecological and evolutionary questions that could be addressed using meta-analyses of large trait databases, and how a trait-based framework could provide valuable insights on the mechanistic links between global changes, functional diversity of fish assemblages, and ecosystem services.  
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  Volume de collection Numéro de collection Edition  
  ISSN 1015-1621 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2211  
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Auteur Escalas, A.; Ferraton, F.; Paillon, C.; Vidy, G.; Carcaillet, F.; Salen-Picard, C.; Le Loc'h, F.; Richard, P.; Darnaude, A.M. doi  openurl
  Titre Spatial variations in dietary organic matter sources modulate the size and condition of fish juveniles in temperate lagoon nursery sites Type Article scientifique
  Année 2015 Publication Revue Abrégée Estuar. Coast. Shelf Sci.  
  Volume 152 Numéro Pages 78-90  
  Mots-Clés coastal lagoon; continental inputs; diet; fish; food webs; fresh-water flow; gilthead sea bream; isotope ratios; lagoon; marine nurseries; nursery; sole solea-solea; sparus-aurata; Stable isotopes; stable-isotopes; trophic ecology  
  Résumé Effective conservation of marine fish stocks involves understanding the impact, on population dynamics, of intra-specific variation in nursery habitats use at the juvenile stage. In some regions, an important part of the catching effort is concentrated on a small number of marine species that colonize coastal lagoons during their first year of life. To determine the intra-specific variation in lagoon use by these fish and their potential demographic consequences, we studied diet spatiotemporal variations in the group 0 juveniles of a highly exploited sparid, the gilthead seabream (Sparus aurata L), during their similar to 6 months stay in a NW Mediterranean lagoon (N = 331, SL = 25-198 mm) and traced the origin of the organic matter in their food webs, at two lagoon sites with contrasted continental inputs. This showed that the origin (marine, lagoonal or continental) of the organic matter (OM) available in the water column and the sediment can vary substantially within the same lagoon, in line with local variations in the intensity of marine and continental inputs. The high trophic plasticity of S. aurata allows its juveniles to adapt to resulting differences in prey abundances at each site during their lagoon residency, thereby sustaining high growth irrespective of the area inhabited within the lagoon. However, continental POM incorporation by the juveniles through their diet (of 21-37% on average depending on the site) is proportional to its availability in the environment and could be responsible for the greater fish sizes (of 28 mm SL on average) and body weights (of 40.8 g on average) observed at the site under continental influence in the autumn, when the juveniles are ready to leave the lagoon. This suggests that continental inputs in particulate OM, when present, could significantly enhance fish growth within coastal lagoons, with important consequences on the local population dynamics of the fish species that use them as nurseries. As our results indicate that continental OM can represent up to 62% of the flesh of the juveniles originating from these ecosystems, particular care should be taken to preserve or improve the chemical quality of riverine inputs to coastal lagoons. (C) 2014 Elsevier Ltd. All rights reserved.  
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  ISSN 0272-7714 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1192  
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Auteur Alix, M.; Blondeau-Bidet, E.; Grousset, E.; Shiranghi, A.; Vergnet, A.; Guinand, B.; Chatain, B.; Boulo, V.; Lignot, J.-H. doi  openurl
  Titre Effects of fasting and re-alimentation on gill and intestinal morphology and indicators of osmoregulatory capacity in genetically selected sea bass (Dicentrarchus labrax) populations with contrasting tolerance to fasting Type Article scientifique
  Année 2017 Publication Revue Abrégée Aquaculture  
  Volume 468 Numéro Pages 314-325  
  Mots-Clés bream sparus-auratus; dietary-sodium chloride; Enterocyte; Fasting; feed deprivation; fish; fresh-water; fundulus-heteroclitus; Gill ionocyte; Morphometry; Ontogeny; oreochromis-mossambicus; Osmoregulation; rainbow-trout; Re-alimentation; Salinity; Sea bass  
  Résumé Fasting and refeeding occur naturally in predators but this is largely ignored when dealing with farmed fish. Therefore,the effects of 3-week fasting and re-alimentation (2.5% of the individual body mass) were investigated using two genetically selected populations (F2 generation) of 250 g juvenile sea bass (Dicentrarchus labrax L.). Blood osmolarity, gill and intestinal morphology and expression of the sodium pump (Na+, K+-ATPase, NKA) were studied on two phenotypes showing different degrees of body mass loss during food deprivation: one group losing body mass rapidly during fasting (F+) and the other one limiting body mass loss during the same period (F-). Blood osmotic pressure significantly decreases due to re-alimentation in both groups, but this is compensated in the F+ group. In this group, gill ionocytes are smaller and less numerous, but a significantly higher NKA gene expression is noted in the gills in comparison to the F- individuals 48 and 72 h after re-alimentation, and also in the posterior intestine 72 h after re-alimentation. This most probably occurs to compensate for a higher salt intake during nutrient absorption in comparison to the F- group. Furthermore, refed F- fish absorb more lipids along the proximal anterior intestine, and take longer to digest than the F+ group, and show enterocyte vacuolization in the posterior intestine. Therefore, the two selected populations have different postprandial digestive strategies: the F- fish optimize feed efficiency first at the cost of optimal hydromineral adjustment, while the F+ group invests in osmoregulatory performance at the expense of digestive physiology. Statement of relevance: Our paper is highly relevant to the general field of commercial aquaculture. There is an increasing number of research articles dealing with fasting and refeeding in commercial fish and how to improve fish nutrition based oh these physiological data and genetic selection. (C) 2016 Elsevier B.V. All rights reserved.  
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  ISSN 0044-8486 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1712  
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