bascule de visibilité Search & Display Options

Tout Sélectionner    Désélectionner
 |   | 
Détails
   print
  Enregistrements Liens
Auteur RANJBAR, M.S.; ZOLGHARNIEN, H.; YAVARI, V.; ARCHANGI, B.; SALARI, M.A.; ARNAUD-HAOND, S.; CUNHA, R.L. url  doi
openurl 
  Titre Rising the Persian Gulf Black-Lip Pearl Oyster to the Species Level: Fragmented Habitat and Chaotic Genetic Patchiness in Pinctada persica Type Article scientifique
  Année (down) 2016 Publication Revue Abrégée Evolutionary Biology  
  Volume 43 Numéro 1 Pages 131-143  
  Mots-Clés Black-lip pearl oysters; Fragmented habitat; Persian Gulf; Pinctada persica; Species delimitation  
  Résumé Marine organisms with long pelagic larval stages are expected to exhibit low genetic differentiation due to their potential to disperse over large distances. Growing body of evidence, however, suggests that marine populations can differentiate over small spatial scales. Here we focused on black-lip pearl oysters from the Persian Gulf that are thought to belong to the Pinctada margaritifera complex given their morphological affinities. This species complex includes seven lineages that show a wide distribution ranging from the Persian Gulf (Pinctada margaritifera persica) and Indian Ocean (P. m. zanzibarensis) to the French Polynesia (P. m. cumingii) and Hawai'i (P. m. galtsoffi). Despite the long pelagic larval phase of P. m. persica, this lineage is absent from continental locations and can only be found on a few islands of the Persian Gulf. Mitochondrial COI-based analyses indicated that P. m. persica belongs to a clearly divergent ESU and groups with specimens from Mauritius (P. m. zanzibarensis). Microsatellite data, used here to assess the spatial scale of realized dispersal of Persian Gulf black-lip pearl oysters, revealed significant genetic structure among islands distant of only a few dozen kilometres. The scantiness of suitable habitats most likely restricted the distribution of this lineage originating the observed chaotic genetic patchiness. The hatchery-based enhancement performed in one of the sampled islands may also have affected population genetic structure. The long-term accumulation of genetic differences likely resulted from the allopatric divergence between P. m. persica and the neighbouring Indian Ocean black-lip pearl oysters.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0071-3260 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1519  
Lien permanent pour cet enregistrement
 

 
Auteur Rossi, F.; Baeta, A.; Marques, J.C. doi  openurl
  Titre Stable isotopes reveal habitat-related diet shifts in facultative deposit-feeders Type Article scientifique
  Année (down) 2015 Publication Revue Abrégée J. Sea Res.  
  Volume 95 Numéro Pages 172-179  
  Mots-Clés Benthos; burying depth; carbon; Estuaries; estuarine habitats; food-web; Macrofauna; marine; polychaete nereis-diversicolor; scrobicularia-plana; Seagrass; seagrass meadows; Sediment; water-flow; zostera-noltii  
  Résumé Seagrass patches interspersed in a sediment matrix may vary environmental conditions and affect feeding habits of consumers and food-web structure. This paper investigates diet shifts between bare sediments and a Zostera noltei (Hornemann, 1832) meadow for three facultative deposit-feeding macrofaunal consumers, notably the bivalve Scrobicularia piano (da Costa, 1778), the polychaete Hediste diversicolor (O.T. Muller, 1776), and the gastropod Hydrobia ulvae (Pennant, 1778). In July 2008, one eelgrass meadow and two bare sediment locations were chosen in the Mondego estuary (40 degrees 08" N, 8 degrees 50'W, Portugal) and sampled for stable isotope signatures (delta C-13 and delta N-15) of macrofauna consumers and some of their potential basal food sources, such as sedimentary organic matter (SOM), microphytobenthos (MPB), seagrass shoots, leaves and seaweeds laying on the surface sediment. The delta N-15 of H. diversicolor was 3% higher in the eelgrass meadow than in bare sediment, indicating a change of trophic position, whereas the Bayesian stable-isotope mixing model showed that S. piano assimilated more macroalgal detritus than microphytobenthos in the eelgrass bed. Such habitat-related diet shifts have the potential to change structure and spatial dynamics of benthic food webs. (C) 2014 Elsevier B.V. All rights reserved.  
  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 1385-1101 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 1549  
Lien permanent pour cet enregistrement
 

 
Auteur Boyd, C.; Castillo, R.; Hunt, G.L.; Punt, A.E.; VanBlaricom, G.R.; Weimerskirch, H.; Bertrand, S. url  doi
openurl 
  Titre Predictive modelling of habitat selection by marine predators with respect to the abundance and depth distribution of pelagic prey Type Article scientifique
  Année (down) 2015 Publication Revue Abrégée J Anim Ecol  
  Volume 84 Numéro 6 Pages 1575-1588  
  Mots-Clés central place foragers; Foraging ecology; habitat use; Humboldt Current system; predator–prey interactions; spatial distribution  
  Résumé * Understanding the ecological processes that underpin species distribution patterns is a fundamental goal in spatial ecology. However, developing predictive models of habitat use is challenging for species that forage in marine environments, as both predators and prey are often highly mobile and difficult to monitor. Consequently, few studies have developed resource selection functions for marine predators based directly on the abundance and distribution of their prey. * We analysed contemporaneous data on the diving locations of two seabird species, the shallow-diving Peruvian Booby (Sula variegata) and deeper diving Guanay Cormorant (Phalacrocorax bougainvilliorum), and the abundance and depth distribution of their main prey, Peruvian anchoveta (Engraulis ringens). Based on this unique data set, we developed resource selection functions to test the hypothesis that the probability of seabird diving behaviour at a given location is a function of the relative abundance of prey in the upper water column. * For both species, we show that the probability of diving behaviour is mostly explained by the distribution of prey at shallow depths. While the probability of diving behaviour increases sharply with prey abundance at relatively low levels of abundance, support for including abundance in addition to the depth distribution of prey is weak, suggesting that prey abundance was not a major factor determining the location of diving behaviour during the study period. * The study thus highlights the importance of the depth distribution of prey for two species of seabird with different diving capabilities. The results complement previous research that points towards the importance of oceanographic processes that enhance the accessibility of prey to seabirds. The implications are that locations where prey is predictably found at accessible depths may be more important for surface foragers, such as seabirds, than locations where prey is predictably abundant. * Analysis of the relative importance of abundance and accessibility is essential for the design and evaluation of effective management responses to reduced prey availability for seabirds and other top predators in marine systems.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1365-2656 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1349  
Lien permanent pour cet enregistrement
 

 
Auteur van Gils, J.A.; van der Geest, M.; De Meulenaer, B.; Gillis, H.; Piersma, T.; Folmer, E.O. url  doi
openurl 
  Titre Moving on with foraging theory: incorporating movement decisions into the functional response of a gregarious shorebird Type Article scientifique
  Année (down) 2015 Publication Revue Abrégée Journal of Animal Ecology  
  Volume 84 Numéro Pages 554-564  
  Mots-Clés competition continuous-time Markov chain cryptic interference diet distribution habitat choice intake rate movement ecology predation toxic prey SPATIAL-DISTRIBUTION RED KNOTS MODELING INTERFERENCE CRYPTIC INTERFERENCE STOCHASTIC VERSION BEHAVIORAL ECOLOGY MULTISTATE MODELS BANC-DARGUIN GROUP-SIZE PREY Ecology Zoology  
  Résumé 1. Models relating intake rate to food abundance and competitor density (generalized functional response models) can predict forager distributions and movements between patches, but we lack understanding of how distributions and small-scale movements by the foragers themselves affect intake rates. Using a state-of-the-art approach based on continuous-time Markov chain dynamics, we add realism to classic functional response models by acknowledging that the chances to encounter food and competitors are influenced by movement decisions, and, vice versa, that movement decisions are influenced by these encounters. We used a multi-state modelling framework to construct a stochastic functional response model in which foragers alternate between three behavioural states: searching, handling and moving. Using behavioural observations on a molluscivore migrant shorebird (red knot, Calidris canutus canutus), at its main wintering area (Banc d'Arguin, Mauritania), we estimated transition rates between foraging states as a function of conspecific densities and densities of the two main bivalve prey. Intake rate decreased with conspecific density. This interference effect was not due to decreased searching efficiency, but resulted from time lost to avoidance movements. Red knots showed a strong functional response to one prey (Dosinia isocardia), but a weak response to the other prey (Loripes lucinalis). This corroborates predictions from a recently developed optimal diet model that accounts for the mildly toxic effects due to consuming Loripes. Using model averaging across the most plausible multi-state models, the fully parameterized functional response model was then used to predict intake rate for an independent data set on habitat choice by red knot. Comparison of the sites selected by red knots with random sampling sites showed that the birds fed at sites with higher than average Loripes and Dosinia densities, that is sites for which we predicted higher than average intake rates. We discuss the limitations of Holling's classic functional response model which ignores movement and the limitations of contemporary movement ecological theory that ignores consumer-resource interactions. With the rapid advancement of technologies to track movements of individual foragers at fine spatial scales, the time is ripe to integrate descriptive tracking studies with stochastic movement-based functional response models.  
  Adresse [van Gils, Jan A.; van der Geest, Matthijs; De Meulenaer, Brecht; Gillis, Hanneke; Piersma, Theunis; Folmer, Eelke O.] NIOZ Royal Netherlands Inst Sea Res, Dept Marine Ecol, NL-1790 AB Den Burg, Texel, Netherlands. [van der Geest, Matthijs; Piersma, Theunis] Univ Groningen, Anim Ecol Grp, Ctr Ecol & Evolutionary Studies CEES, Chair Global Flyway Ecol, NL-9700 CC Groningen, Netherlands. van Gils, JA (reprint author), NIOZ Royal Netherlands Inst Sea Res, Dept Marine Ecol, POB 59, NL-1790 AB Den Burg, Texel, Netherlands. Jan.van.Gils@nioz.nl  
  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 0021-8790 ISBN Médium  
  Région Expédition Conférence  
  Notes ISI Document Delivery No.: CB9RB Times Cited: 0 Cited Reference Count: 61 van Gils, Jan A. van der Geest, Matthijs De Meulenaer, Brecht Gillis, Hanneke Piersma, Theunis Folmer, Eelke O. NWO WOTRO [W.01.65.221.00]; NWO [R 84-639]; NWO VIDI [864.09.002] We thank Parc National du Banc d'Arguin (PNBA) for their hospitality, the hosting of our presence and the permission to work in and from the Iwik scientific station. Lemhaba ould Yarba made the logistic arrangements. Joop van Eerbeek, Erik J. Jansen, Han Olff and El-Hacen Mohamed El-Hacen helped collecting and sorting benthos samples. Valuable comments on the manuscript were given by Allert Bijleveld, Jaap van der Meer, Ola Olsson, Thomas Oudman, Isabel M. Smallegange, an anonymous referee and by the 'literature club' of the Centre for Integrative Ecology during JAvG's sabbatical at Deakin University. Dick Visser polished the figures. This work is supported by an NWO WOTRO Integrated Programme grant (W.01.65.221.00) to TP, an NWO travel grant (R 84-639) to EOF, and an NWO VIDI grant (864.09.002) to JAvG. 0 WILEY-BLACKWELL HOBOKEN J ANIM ECOL Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ 1412 collection 1383  
Lien permanent pour cet enregistrement
 

 
Auteur Mazel, F.; Renaud, J.; Guilhaumon, F.; Mouillot, D.; Gravel, D.; Thuiller, W. url  doi
openurl 
  Titre Mammalian phylogenetic diversity-area relationships at a continental scale Type Article scientifique
  Année (down) 2015 Publication Revue Abrégée Ecology  
  Volume 96 Numéro 10 Pages 2814-2822  
  Mots-Clés Biodiversity; Biogeography; community ecology; conservation; conservation biogeography; habitat loss; habitat loss; null models; overestimate extinction rates; patterns; phylogenetic diversity; richness; species-area; species-area relationship; statistics; strict nested design  
  Résumé In analogy to the species-area relationship (SAR), one of the few laws in ecology, the phylogenetic diversity-area relationship (PDAR) describes the tendency of phylogenetic diversity (PD) to increase with area. Although investigating PDAR has the potential to unravel the underlying processes shaping assemblages across spatial scales and to predict PD loss through habitat reduction, it has been little investigated so far. Focusing on PD has noticeable advantages compared to species richness (SR), since PD also gives insights on processes such as speciation/extinction, assembly rules and ecosystem functioning. Here we investigate the universality and pervasiveness of the PDAR at continental scale using terrestrial mammals as study case. We define the relative robustness of PD (compared to SR) to habitat loss as the area between the standardized PDAR and standardized SAR (i.e., standardized by the diversity of the largest spatial window) divided by the area under the standardized SAR only. This metric quantifies the relative increase of PD robustness compared to SR robustness. We show that PD robustness is higher than SR robustness but that it varies among continents. We further use a null model approach to disentangle the relative effect of phylogenetic tree shape and nonrandom spatial distribution of evolutionary history on the PDAR. We find that, for most spatial scales and for all continents except Eurasia, PDARs are not different from expected by a model using only the observed SAR and the shape of the phylogenetic tree at continental scale. Interestingly, we detect a strong phylogenetic structure of the Eurasian PDAR that can be predicted by a model that specifically account for a finer biogeographical delineation of this continent. In conclusion, the relative robustness of PD to habitat loss compared to species richness is determined by the phylogenetic tree shape but also depends on the spatial structure of PD.  
  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 0012-9658 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1423  
Lien permanent pour cet enregistrement
Tout Sélectionner    Désélectionner
 |   | 
Détails
   print

Save Citations:
Export Records: