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Auteur Masroor, W.; Farcy, E.; Gros, R.; Lorin-Nebel, C. doi  openurl
  Titre Effect of combined stress (salinity and temperature) in European sea bass Dicentrarchus labrax osmoregulatory processes Type Article scientifique
  Année 2018 Publication Revue Abrégée Comp. Biochem. Physiol. A-Mol. Integr. Physiol.  
  Volume (down) 215 Numéro Pages 45-54  
  Mots-Clés Osmoregulation; fresh-water; Teleost; goldfish carassius-auratus; Ionocytes; branchial na+/k+-atpase; fish gills; gill morphology; Gill plasticity; Hydromineral balance; k+-atpase activity; mitochondria-rich cells; mozambique tilapia; NKA activity; salmon salmo-salar; Thermal acclimation; tilapia oreochromis-mossambicus  
  Résumé European sea bass Dicentrarchus Iabrax undertake seasonal migrations to estuaries and lagoons that are characterized by fluctuations in environmental conditions. Their ability to cope with these unstable habitats is undeniable, but it is still not clear how and to what extent salinity acclimation mechanisms are affected at temperatures higher than in the sea. In this study, juvenile sea bass were pre-acclimated to seawater (SW) at 18 degrees C (temperate) or 24 degrees C (warm) for 2 weeks and then transferred to fresh water (FW) or SW at the respective temperature. Transfer to FW for two weeks resulted in decreased blood osmolalities and plasma Cl- at both temperatures. In FW warm conditions, plasma Na+ was similar to 15% lower and Cl- was similar to 32% higher than in the temperate-water group. Branchial Na+/K+-ATPase (NKA) activity measured at the acclimation temperature (V-apparent) did not change according to the conditions. Branchial Na+/K+-ATPase activity measured at 37 degrees C (V-max) was lower in warm conditions and increased in FW compared to SW conditions whatever the considered temperature. Mitochondrion-rich cell (MRC) density increased in FW, notably due to the appearance of lamellar MRCs, but this increase was less pronounced in warm conditions where MRC's size was lower. In SW warm conditions, pavement cell apical microridges are less developed than in other conditions. Overall gill morphometrical parameters (filament thickness, lamellar length and width) differ between fish that have been pre acclimated to different temperatures. This study shows that a thermal change affects gill plasticity affecting whole-organism ion balance two weeks after salinity transfer.  
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  Langue English Langue du Résumé Titre Original  
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  ISSN 1095-6433 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2260  
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Auteur Escalas, A.; Catherine, A.; Maloufi, S.; Cellamare, M.; Hamlaoui, S.; Yepremian, C.; Louvard, C.; Troussellier, M.; Bernard, C. doi  openurl
  Titre Drivers and ecological consequences of dominance in periurban phytoplankton communities using networks approaches Type Article scientifique
  Année 2019 Publication Revue Abrégée Water Res.  
  Volume (down) 163 Numéro Pages Unsp-114893  
  Mots-Clés blooms; climate-change; Co-occurrence network; Community cohesion; Community functioning; cooccurrence patterns; cyanobacteria dominance; diversity; Dominance; fresh-waters; lakes; light; Periurban waterbodies; Phytoplankton; resource use efficiency; species richness  
  Résumé Evaluating the causes and consequences of dominance by a limited number of taxa in phytoplankton communities is of huge importance in the current context of increasing anthropogenic pressures on natural ecosystems. This is of particular concern in densely populated urban areas where usages and impacts of human populations on water ecosystems are strongly interconnected. Microbial biodiversity is commonly used as a bioindicator of environmental quality and ecosystem functioning, but there are few studies at the regional scale that integrate the drivers of dominance in phytoplankton communities and their consequences on the structure and functioning of these communities. Here, we studied the causes and consequences of phytoplankton dominance in 50 environmentally contrasted waterbodies, sampled over four summer campaigns in the highly-populated Ile-de-France region (IDF). Phytoplankton dominance was observed in 32-52% of the communities and most cases were attributed to Chlorophyta (35.5-40.6% of cases) and Cyanobacteria (30.3-36.5%). The best predictors of dominance were identified using multinomial logistic regression and included waterbody features (surface, depth and connection to the hydrological network) and water column characteristics (total N, TN:TP ratio, water temperature and stratification). The consequences of dominance were dependent on the identity of the dominant organisms and included modifications of biological attributes (richness, cohesion) and functioning (biomass, RUE) of phytoplankton communities. We constructed co-occurrence networks using high resolution phytoplankton biomass and demonstrated that networks under dominance by Chlorophyta and Cyanobacteria exhibited significantly different structure compared with networks without dominance. Furthermore, dominance by Cyanobacteria was associated with more profound network modifications (e.g. cohesion, size, density, efficiency and proportion of negative links), suggesting a stronger disruption of the structure and functioning of phytoplankton communities in the conditions in which this group dominates. Finally, we provide a synthesis on the relationships between environmental drivers, dominance status, community attributes and network structure. (C) 2019 Elsevier Ltd. All rights reserved.  
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  ISSN 0043-1354 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000483006400038 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2636  
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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 (down) 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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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0272-7714 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1192  
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Auteur Gerber, L.; Lee, C.E.; Grousset, E.; Blondeau-Bidet, E.; Boucheker, N.B.; Lorin-Nebel, C.; Charmantier-Daures, M.; Charmantier, G. doi  openurl
  Titre The Legs Have It: In Situ Expression of Ion Transporters V-Type H+-ATPase and Na+/K+-ATPase in the Osmoregulatory Leg Organs of the Invading Copepod Eurytemora affinis Type Article scientifique
  Année 2016 Publication Revue Abrégée Physiol. Biochem. Zool.  
  Volume (down) 89 Numéro 3 Pages 233-250  
  Mots-Clés crab chasmagnathus-granulatus; crustacea; euryhaline crabs; fresh-water crab; immunolocalization; integumental windows; ionic regulation; malpighian tubules; messenger-rna expression; Na+/K+-ATPase; Osmoregulation; posterior gills; salinity acclimation; shrimp macrobrachium-amazonicum; swimming legs; V-type H+-ATPase  
  Résumé The copepod Eurytemora affinis has an unusually broad salinity range, as some populations have recently invaded freshwater habitats independently from their ancestral saline habitats. Prior studies have shown evolutionary shifts in ion transporter activity during freshwater invasions and localization of ion transporters in newly discovered “Crusalis organs” in the swimming legs. The goals of this study were to localize and quantify expression of ion transport enzymes V-type H+-ATPase (VHA) and Na+/K+-ATPase (NKA) in the swimming legs of E. affinis and determine the degree of involvement of each leg in ionic regulation. We confirmed the presence of two distinct types of ionocytes in the Crusalis organs. Both cell types expressed VHA and NKA, and in the freshwater population the location of VHA and NKA in ionocytes was, respectively, apical and basal. Quantification of in situ expression of NKA and VHA established the predominance of swimming leg pairs 3 and 4 in ion transport in both saline and freshwater populations. Increases in VHA expression in swimming legs 3 and 4 of the freshwater population (in fresh water) relative to the saline population (at 15 PSU) arose from an increase in the abundance of VHA per cell rather than an increase in the number of ionocytes. This result suggests a simple mechanism for increasing ion uptake in fresh water. In contrast, the decline in NKA expression in the freshwater population arose from a decrease in ionocyte area in legs 4, likely resulting from decreases in number or size of ionocytes containing NKA. Such results provide insights into mechanisms of ionic regulation for this species, with added insights into evolutionary mechanisms underlying physiological adaptation during habitat invasions.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 1522-2152 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1622  
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Auteur Masroor, W.; Farcy, E.; Blondeau-Bidet, E.; Venn, A.; Tambutte, E.; Lorin-Nebel, C. doi  openurl
  Titre Effect of salinity and temperature on the expression of genes involved in branchial ion transport processes in European sea bass Type Article scientifique
  Année 2019 Publication Revue Abrégée J. Therm. Biol.  
  Volume (down) 85 Numéro Pages Unsp-102422  
  Mots-Clés cftr anion channel; chloride channel; cod gadus-morhua; Dicentrarchus labrax; dicentrarchus-labrax; fresh-water; functional classification; Gill; h+-atpase; Ion transporter; mRNA expression; na+/k+-atpase; na+/k+/2cl(-) cotransporter; Salinity; seawater-acclimated medaka; Thermal acclimation  
  Résumé The responses of European sea bass to temperature increase and salinity decrease were investigated measuring mRNA expression levels of main genes involved in ion transport. Juvenile fish were pre-acclimated to seawater (SW) at 18 degrees C (temperate) or 24 degrees C (warm) for two weeks and then transferred for two weeks to either fresh water (FW) or SW at the respective temperature. Unlike temperate conditions, there is no change in Na+/K+-ATPase ala (nka ala) and Na+/H+ exchanger 3 (nhe3) mRNA expression following FW transfer in warm conditions. This is linked to the high expression of these genes in warm SW compared to temperate SW. Na+/Cl--cotransporter (ncc2a) expression however is increased following FW transfer in temperate and warm conditions. Main transporters involved in ion excretion (Na+/K+/2Cl-1( )cotransporter, nkcc1 and cystic fibrosis transmembrane conductance regulator, cftr) as well as nitrogen excretion (Rh-glycoproteins, rhcg1 and rhbg) and acid-base regulation (V-H+-ATPase, vha-a and b) are highly expressed in SW warm conditions vs FW warm. Overall, our results suggest a higher activation of ion transport processes in warm conditions and more strikingly in SW. This is linked to a strong interplay between diverse ion transporters in order to coordinate physiological responses at the gill level.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0306-4565 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000497246100023 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2669  
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