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Auteur (up) Grzebyk, D.; Audic, S.; Lasserre, B.; Abadie, E.; de Vargas, C.; Bec, B. doi  openurl
  Titre Insights into the harmful algal flora in northwestern Mediterranean coastal lagoons revealed by pyrosequencing metabarcodes of the 28S rRNA gene Type Article scientifique
  Année 2017 Publication Revue Abrégée Harmful Algae  
  Volume 68 Numéro Pages 1-16  
  Mots-Clés Phytoplankton diversity; Harmful algae; Monitoring; alexandrium dinophyceae; dinoflagellate stoeckeria-changwonensis; domoic acid accumulation; eastern adriatic sea; Metabarcoding; partial lsu rdna; pfiesteria-piscicida dinophyceae; phylogenetic-relationships; pseudo-nitzschia bacillariophyceae; species complex dinophyceae; toxic dinoflagellate  
  Résumé This study investigated the genetic diversity of phytoplankton communities in six shallow lagoons located on the French coast of the northwestern Mediterranean Sea that represented a trophic gradient ranging from oligotrophic to hypereutrophic. The phytoplankton communities were sampled once a month from spring (May) to the beginning of autumn (September/early October) in 2012 and fractionated by size. Metabarcodes were generated from cDNAs by targeting the D1-D2 region of the 28S rRNA gene and pyrosequenced using Roche 454 technology. Examination of the annotated barcodes revealed harmful algal species not previously documented in these lagoons. Three ichthyotoxic species belonging to Pfiesteriaceae were detected: Luciella masanensis was relatively widespread and abundant in many samples, whereas Pfiesteria piscicida and Stoeckeria changwonensis were found as single barcode sequences. Furthermore, a phylogenetic analysis of barcodes annotated as belonging to Pfiesteriaceae suggested the existence of two previously undescribed clades. The other toxic or potentially harmful dinoflagellates detected through rare barcodes were Dinophysis acuminata, Vulcanodinium rugosum, Alexandrium andersonii and A. ostenfeldii. The two most abundant dinoflagellate taxa were Gymnodinium litoralis and Akashiwo sanguinea with respect to sequence numbers. Four diatom species from the genus Pseudo-nitzschia that potentially produce domoic acid were identified (P. galaxiae, P. delicatissima, P. brasiliana and P. calliantha). These observations are discussed in terms of the literature and monitoring records related to the identified taxa in this Mediterranean area. (C) 2017 Elsevier B.V. All rights reserved.  
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  ISSN 1568-9883 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2227  
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Auteur (up) Hoffle, H.; Van Damme, C.J.G.; Fox, C.; Lelievre, S.; Loots, C.; Nash, R.D.M.; Vaz, S.; Wright, P.J.; Munk, P. doi  openurl
  Titre Linking spawning ground extent to environmental factors – patterns and dispersal during the egg phase of four North Sea fishes Type Article scientifique
  Année 2018 Publication Revue Abrégée Can. J. Fish. Aquat. Sci.  
  Volume 75 Numéro 3 Pages 357-374  
  Mots-Clés climate-change; spatial distributions; cod gadus-morhua; neighbor matrices; offshore oil; generalized additive-models; dependent development rates; haddock melanogrammus-aeglefinus; pleuronectes-platessa l; whiting merlangius-merlangus  
  Résumé Previous studies have shown that four commercially important demersal species, namely Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and European plaice (Pleuronectes platessa), spawn in distinct areas across the North Sea. Based on two comprehensive ichthyoplankton surveys in 2004 and 2009, the present study uses generalized additive mixed models to delimit these spawning grounds using the distribution of recently spawned eggs, investigates their relationship to specific environmental conditions, and examines egg dispersal during their development. Results indicate that presence-absence of early stage eggs is more related to temporal and topographic variables, while egg densities are closely linked with hydrography. Egg distribution patterns were relatively consistent during development and only changed near hatching. Compared with historic observations, the location of the spawning grounds appeared stable on the broad scale but centres of egg abundance varied between the surveyed years. Potential effects of long-term climate change and anthropogenic short-term disturbances, such as seismic surveys, on fish reproduction are discussed, pointing out the demand for multispecies studies on these issues.  
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  ISSN 0706-652x ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2316  
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Auteur (up) Hugoni, M.; Escalas, A.; Bernard, C.; Nicolas, S.; Jézéquel, D.; Vazzoler, F.; Sarazin, G.; Leboulanger, C.; Bouvy, M.; Got, P.; Ader, M.; Troussellier, M.; Agogué, H. url  doi
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  Titre Spatiotemporal variations in microbial diversity across the three domains of life in a tropical thalassohaline lake (Dziani Dzaha, Mayotte Island) Type Article scientifique
  Année 2018 Publication Revue Abrégée Molecular Ecology  
  Volume 27 Numéro 23 Pages 4775-4786  
  Mots-Clés archaea; bacteria; eukaryotes; extreme environment; metabarcoding; thalassohaline lake  
  Résumé Thalassohaline ecosystems are hypersaline environments originating from seawater in which sodium chloride is the most abundant salt and the pH is alkaline. Studies focusing on microbial diversity in thalassohaline lakes are still scarce compared with those on athalassohaline lakes such as soda lakes that have no marine origin. In this work, we investigated multiple facets of bacterial, archaeal and eukaryotic diversity in the thalassohaline Lake Dziani Dzaha using a metabarcoding approach. We showed that bacterial and archaeal diversity were mainly affected by contrasting physicochemical conditions retrieved at different depths. While photosynthetic microorganisms were dominant in surface layers, chemotrophic phyla (Firmicutes or Bacteroidetes) and archaeal methanogens dominated deeper layers. In contrast, eukaryotic diversity was constant regardless of depth and was affected by seasonality. A detailed focus on eukaryotic communities showed that this constant diversity profile was the consequence of the high predominance of Picocystis salinarum, while nondominant eukaryotic groups displayed seasonal diversity turnover. Altogether, our results provided an extensive description of the diversity of the three domains of life in an unexplored extreme environment and showed clear differences in the responses of prokaryotic and eukaryotic communities to environmental conditions.  
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  ISSN 1365-294x ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2460  
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Auteur (up) Iversen, N.K.; McKenzie, D.J.; Malte, H.; Wang, T. url  doi
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  Titre Reflex bradycardia does not influence oxygen consumption during hypoxia in the European eel (Anguilla anguilla) Type Article scientifique
  Année 2010 Publication Revue Abrégée J. Comp. Physiol. B-Biochem. Syst. Environ. Physiol.  
  Volume 180 Numéro 4 Pages 495-502  
  Mots-Clés Anguilla anguilla; Cardiac output; Critical oxygen tension; Hypoxic bradycardia; Oxygen; Teleost; atlantic cod; cardiac vagotomy; circulation; consumption; dogfish scyliorhinus-canicula; fish; heart-rate; rainbow-trout; responses; temperature; tolerance  
  Résumé Most teleost fish reduce heart rate when exposed to acute hypoxia. This hypoxic bradycardia has been characterised for many fish species, but it remains uncertain whether this reflex contributes to the maintenance of oxygen uptake in hypoxia. Here we describe the effects of inhibiting the bradycardia on oxygen consumption (MO(2)), standard metabolic rate (SMR) and the critical oxygen partial pressure for regulation of SMR in hypoxia (Pcrit) in European eels Anguilla anguilla (mean +/- A SEM mass 528 +/- A 36 g; n = 14). Eels were instrumented with a Transonic flow probe around the ventral aorta to measure cardiac output (Q) and heart rate (f (H)). MO(2) was then measured by intermittent closed respirometry during sequential exposure to various levels of increasing hypoxia, to determine Pcrit. Each fish was studied before and after abolition of reflex bradycardia by intraperitoneal injection of the muscarinic antagonist atropine (5 mg kg(-1)). In the untreated eels, f (H) fell from 39.0 +/- A 4.3 min(-1) in normoxia to 14.8 +/- A 5.2 min(-1) at the deepest level of hypoxia (2 kPa), and this was associated with a decline in Q, from 7.5 +/- A 0.8 mL min(-1) kg(-1) to 3.3 +/- A 0.7 mL min(-1) kg(-1) in normoxia versus deepest hypoxia, respectively. Atropine had no effect on SMR, which was 16.0 +/- A 1.8 mu mol O(2) kg(-1) min(-1) in control versus 16.8 +/- A 0.8 mu mol O(2) kg(-1) min(-1) following treatment with atropine. Atropine also had no significant effect on normoxic f (H) or Q in the eel, but completely abolished the bradycardia and associated decline in Q during progressive hypoxia. This pharmacological inhibition of the cardiac responses to hypoxia was, however, without affect on Pcrit, which was 11.7 +/- A 1.3 versus 12.5 +/- A 1.5 kPa in control versus atropinised eels, respectively. These results indicate, therefore, that reflex bradycardia does not contribute to maintenance of MO(2) and regulation of SMR by the European eel in hypoxia.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0174-1578 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 805  
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Auteur (up) Jorgensen, C.; Peck, M.A.; Antognarelli, F.; Azzurro, E.; Burrows, M.T.; Cheung, W.W.L.; Cucco, A.; Holt, R.E.; Huebert, K.B.; Marras, S.; McKenzie, D.; Metcalfe, J.; Perez-Ruzafa, A.; Sinerchia, M.; Steffensen, J.F.; Teal, L.R.; Domenici, P. doi  openurl
  Titre Conservation physiology of marine fishes: advancing the predictive capacity of models Type Article scientifique
  Année 2012 Publication Revue Abrégée Biol. Lett.  
  Volume 8 Numéro 6 Pages 900-903  
  Mots-Clés atlantic cod; body-mass; climate-change; climate effects; conservation physiology; gadus-morhua; metabolic scope; modelling; ocean; species distribution; temperature  
  Résumé At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology to different extents, ranging from no explicit consideration to detailed physiological mechanisms, and across scales from a single fish to global fishery resources. Biologists from different sub-disciplines are collaborating to rise to the challenge of projecting future changes in distribution and productivity, assessing risks for local populations, or predicting and mitigating the spread of invasive species.  
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  Volume de collection Numéro de collection Edition  
  ISSN 1744-9561 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1432  
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