bascule de visibilité Search & Display Options

Tout Sélectionner    Désélectionner
 |   | 
Détails
   print
  Enregistrements Liens
Auteur Gounand, I.; Daufresne, T.; Gravel, D.; Bouvier, C.; Bouvier, T.; Combe, M.; Gougat-Barbera, C.; Poly, F.; Torres-Barcelo, C.; Mouquet, N. doi  openurl
  Titre Size evolution in microorganisms masks trade-offs predicted by the growth rate hypothesis Type Article scientifique
  Année 2016 Publication Revue Abrégée Proc. R. Soc. B-Biol. Sci.  
  Volume 283 Numéro (up) 1845 Pages 20162272  
  Mots-Clés Bacteria; bacterial community; biological stoichiometry; cell-size; escherichia-coli; experimental evolution; fresh-water; growth rate hypothesis; inorganic polyphosphate; intrinsic growth; mechanistic approach; Pseudomonas fluorescens; resource competition; r/K strategies; Stoichiometry; variable environment  
  Résumé Adaptation to local resource availability depends on responses in growth rate and nutrient acquisition. The growth rate hypothesis (GRH) suggests that growing fast should impair competitive abilities for phosphorus and nitrogen due to high demand for biosynthesis. However, in microorganisms, size influences both growth and uptake rates, which may mask trade-offs and instead generate a positive relationship between these traits (size hypothesis, SH). Here, we evolved a gradient of maximum growth rate (mu(max)) from a single bacterium ancestor to test the relationship among mu(max), competitive ability for nutrients and cell size, while controlling for evolutionary history. We found a strong positive correlation between mu(max) and competitive ability for phosphorus, associated with a trade-off between mu(max) and cell size: strains selected for high mu(max) were smaller and better competitors for phosphorus. Our results strongly support the SH, while the trade-offs expected under GRH were not apparent. Beyond plasticity, unicellular populations can respond rapidly to selection pressure through joint evolution of their size and maximum growth rate. Our study stresses that physiological links between these traits tightly shape the evolution of competitive strategies.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  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 0962-8452 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2055  
Lien permanent pour cet enregistrement
 

 
Auteur Panfili, J.; Darnaude, A.M.; Lin, Y.J.; Chevalley, M.; Iizuka, Y.; Tzeng, W.N.; Crivelli, A.J. url  doi
openurl 
  Titre Habitat residence during continental life of the European eel Anguilla anguilla investigated using linear discriminant analysis applied to otolith Sr:Ca ratios Type Article scientifique
  Année 2012 Publication Revue Abrégée Aquat. Biol.  
  Volume 15 Numéro (up) 2 Pages 175-185  
  Mots-Clés Anguilla anguilla; Epma; European eel; La-Icpms; Mediterranean area; Otolith; Strontium:calcium ratio; coastal; elemental fingerprints; estuarine; fish otoliths; fresh-water environments; history; japonica; mass; microchemistry; rostrata; spectrometry; sr-ca ratios  
  Résumé European eel Anguilla anguilla migratory behaviour during continental life is still unclear due to the multiplicity of aquatic environments colonised by the species. In the Camargue area (NW Mediterranean), eel colonisation of the Fumemorte canal, a freshwater habitat that communicates only with a vast brackish ecosystem (the Vaccares lagoon), offers a rare opportunity to test for freshwater habitat residence during continental life. To this end, both laser ablation inductively coupled plasma mass spectrometry and electron probe micro-analysis were used to measure chronological variations of strontium concentrations (Sr:Ca) in the otoliths of 58 silver eels captured in the canal between 1997 and 2007. Comparing mean Sr: Ca ratios measured on otolith edges with the 2 analytical methods indicated that they provide comparable measurement accuracies. Linear discriminant analysis (LDA), based on the otolith Sr: Ca values corresponding to the initial entrance of the fish into the brackish ecosystem and their final capture in the freshwater canal, allowed successful discrimination of the 2 habitats and reconstruction of migratory history for all individuals. Six different migratory behaviours were identified. Eels that entered the freshwater canal did so either directly (67%) or after 1 to 2 yr spent in the lagoon (33%), with a subsequent majority of freshwater residents (55%) until their silvering. These results indicate the value of LDA for reconstructing habitat use during continental life using Sr: Ca ratios. They confirm the occurrence of freshwater residence during continental life in European eels, even in Mediterranean continental areas where brackish environments are predominant. This observed sedentary behaviour has implications for eel population management and conservation.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  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 1864-7790 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 626  
Lien permanent pour cet enregistrement
 

 
Auteur Buisson, L.; Grenouillet, G.; Villeger, S.; Canal, J.; Laffaille, P. url  doi
openurl 
  Titre Toward a loss of functional diversity in stream fish assemblages under climate change Type Article scientifique
  Année 2013 Publication Revue Abrégée Glob. Change Biol.  
  Volume 19 Numéro (up) 2 Pages 387-400  
  Mots-Clés assemblages; biotic homogenization; bird communities; climate change; distribution models; ecosystem; environmental-change; fresh-water biodiversity; functional traits; habitat; no-analog communities; range shifts; species; species distribution; stream fish; traits  
  Résumé The assessment of climate change impacts on biodiversity has so far been biased toward the taxonomic identification of the species likely either to benefit from climate modifications or to experience overall declines. There have still been few studies intended to correlate the characteristics of species to their sensitivity to climate change, even though it is now recognized that functional trait-based approaches are promising tools for addressing challenges related to global changes. In this study, two functional indices (originality and uniqueness) were first measured for 35 fish species occurring in French streams. They were then combined to projections of range shifts in response to climate change derived from species distribution models. We set out to investigate: (1) the relationship between the degrees of originality and uniqueness of fish species, and their projected response to future climate change; and (2) the consequences of individual responses of species for the functional diversity of fish assemblages. After accounting for phylogenetic relatedness among species, we have demonstrated that the two indices used measure two complementary facets of the position of fish species in a functional space. We have also rejected the hypothesis that the most original and/or less redundant species would necessarily experience the greatest declines in habitat suitability as a result of climate change. However, individual species range shifts could lead simultaneously both to a severe decline in the functional diversity of fish assemblages, and to an increase in the functional similarity among assemblages, supporting the hypothesis that disturbance favors communities with combination of common traits and biotic homogenization as well. Our findings therefore emphasize the importance of going beyond the simple taxonomic description of diversity to provide a better assessment of the likely future effects of environmental changes on biodiversity, thus helping to design more effective conservation and management measures.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  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 1354-1013 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 897  
Lien permanent pour cet enregistrement
 

 
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 (up) 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.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  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 0046-5070 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000501987000001 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2703  
Lien permanent pour cet enregistrement
 

 
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 89 Numéro (up) 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.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  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 1522-2152 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 1622  
Lien permanent pour cet enregistrement
Tout Sélectionner    Désélectionner
 |   | 
Détails
   print

Save Citations:
Export Records: