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Registros recuperados: 18 | |
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Boavida, Joana; Paulo, Diogo; Aurelle, Didier; Arnaud-haond, Sophie; Marschal, Christian; Reed, John; Goncalves, Jorge M. S.; Serrao, Ester A.. |
Background The highly valuable red coral Corallium rubrum is listed in several Mediterranean Conventions for species protection and management since the 1980s. Yet, the lack of data about its Atlantic distribution has hindered its protection there. This culminated in the recent discovery of poaching activities harvesting tens of kg of coral per day from deep rocky reefs off SW Portugal. Red coral was irregularly exploited in Portugal between the 1200s and 1700s, until the fishery collapsed. Its occurrence has not been reported for the last 300 years. Results Here we provide the first description of an Atlantic red coral assemblage, recently rediscovered dwelling at 60-100 m depth in southern Portugal. We report a very slow growth rate (0.23 mm year-1),... |
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Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00314/42498/41877.pdf |
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Arnaud-haond, Sophie; Marba, Nuria; Diaz-almela, Elena; Serrao, Ester A.; Duarte, Carlos M.. |
The diversity-stability relationship is the subject of a long-standing debate in ecology, but the genetic component of diversity has seldom been explored. In this study, we analyzed the interplay between genetic diversity and demographic responses to environmental pressures. This analysis included 30 meadows formed by the Mediterranean endemic seagrass, Posidonia oceanica, showing a wide range of population dynamics ranging from a near equilibrium state to steep decline due to strong environmental pressures close to aquaculture installations. Our results show that sedimentation rates are much better predictors of mortality than clonal or genetic components. An unexpected positive trend was observed between genotypic diversity and mortality, along with a... |
Tipo: Text |
Palavras-chave: Seagrass; Demography; Clonality; Genetic richness; Diversity-stability; Posidonia oceanica. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11693/8498.pdf |
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Arnaud-haond, Sophie; Moalic, Yann; Hernandez-garcia, Emilio; Eguiluz, Victor M.; Alberto, Filipe; Serrao, Ester A.; Duarte, Carlos M.. |
The recurrent lack of isolation by distance reported at regional scale in seagrass species was recently suggested to stem from stochastic events of large-scale dispersal. We explored the usefulness of phylogenetic information contained in microsatellite loci to test this hypothesis by using the Genetic Diversity Spectrum (GDS) on databases containing, respectively, 7 and 9 microsatellites genotypes for 1541 sampling units of Posidonia oceanica and 1647 of Cymodocea nodosa. The simultaneous increase of microsatellite and geographic distances that emerges reveals a coherent pattern of isolation by distance in contrast to the chaotic pattern previously described using allele frequencies, in particular, for the long-lived P. oceanica. These results suggest... |
Tipo: Text |
Palavras-chave: Clonality; Genetic Diversity Spectrum; Genetic divergence; Microsatellites; Seagrass; Stepwise mutation. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00182/29292/27733.pdf |
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Aires, Tania; Marba, Nuria; Cunha, Regina L.; Kendrick, Gary A.; Walker, Diana I.; Serrao, Ester A.; Duarte, Carlos M.; Arnaud-haond, Sophie. |
Seagrasses are the structural species of one of the most important coastal ecosystems worldwide and support high levels of biodiversity and biomass production. Posidonia is one of the most ancient seagrass genera and displays a contrasting disjunct biogeographic pattern. It contains one single species in the Northern Hemisphere, P. oceanica, which is endemic to the Mediterranean Sea, and has up to 8 recognized taxa in the Southern Hemisphere, which in Australia are divided into 2 complexes, P. ostenfeldii and P. australis. A phylogeny based on a nuclear marker (rRNA-ITS) revealed an ancient split between the northern (i.e. Mediterranean) and southern (i.e. Australian) taxa, followed by a separation of the 2 recognized Australian complexes. However, the... |
Tipo: Text |
Palavras-chave: Posidonia; Phylogeny; Low evolutionary rates; Ancient diversification. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00027/13798/10937.pdf |
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Massa, Sonia I.; Pearson, Gareth A.; Aires, Tania; Kube, Michael; Olsen, Jeanine L.; Reinhardt, Richard; Serrao, Ester A.; Arnaud Haond, Sophie. |
Predicted global climate change threatens the distributional ranges of species worldwide. We identified genes expressed in the intertidal seagrass Zostera midi during recovery from a simulated low tide heat-shock exposure. Five Expressed Sequence Tag (EST) libraries were compared, corresponding to four recovery times following sub-lethal temperature stress, and a non-stressed control. We sequenced and analyzed 7009 sequence reads from 30 min, 2 h, 4 h and 24 h after the beginning of the heat-shock (AHS), and 1585 from the control library, for a total of 8594 sequence reads. Among 51 Tentative UniGenes (TUGs) exhibiting significantly different expression between libraries, 19 (37.3%) were identified as 'molecular chaperones' and were over-expressed... |
Tipo: Text |
Palavras-chave: EST library; High temperature stress; Abiotic stress response; Climate change. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00044/15559/13326.pdf |
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Neiva, Joao; Pearson, Gareth A.; Valero, Myriam; Serrao, Ester A.. |
Background: Factors promoting the emergence of sharp phylogeographic breaks include restricted dispersal, habitat discontinuity, physical barriers, disruptive selection, mating incompatibility, genetic surfing and secondary contact. Disentangling the role of each in any particular system can be difficult, especially when species are evenly distributed across transition zones and dispersal barriers are not evident. The estuarine seaweed Fucus ceranoides provides a good example of highly differentiated populations along its most persistent distributional range at the present rear edge of the species distribution, in NW Iberia. Intrinsic dispersal restrictions are obvious in this species, but have not prevented F. ceranoides from vastly expanding its range... |
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Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00374/48502/48811.pdf |
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Masucci, A. Paolo; Arnaud-haond, Sophie; Eguiluz, Victor M.; Hernandez-garcia, Emilio; Serrao, Ester A.. |
We analyse a large data set of genetic markers obtained from populations of Cymodocea nodosa, a marine plant occurring from the East Mediterranean to the Iberian-African coasts in the Atlantic Ocean. We fully develop and test a recently introduced methodology to infer the directionality of gene flow based on the concept of geographical segregation. Using the Jensen-Shannon divergence, we are able to extract a directed network of gene flow describing the evolutionary patterns of Cymodocea nodosa. In particular we recover the genetic segregation that the marine plant underwent during its evolution. The results are confirmed by natural evidence and are consistent with an independent cross analysis. |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00127/23872/21805.pdf |
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Arnaud-haond, Sophie; Duarte, Carlos M.; Teixeira, Sara; Massa, Sonia Isabel; Terrados, Jorge; Nguyen Hong, Tri; Phan Nguyen, Hong; Serrao, Ester A.. |
The widespread use of Agent Orange (a mixture of phenoxyl herbicides) over Southern Vietnam by US Forces led to the decimation of mangrove forests in the Mekong Delta. Mangrove trees Avicennia alba were sampled across the Mekong Delta; their age was assessed using models based on internode growth and samples were genotyped for 6 microsatellite loci. The evolution of genetic diversity over time elapsed since local extinction was reconstructed and compared with the genetic diversity of an unaffected population from Thailand, The results show that genetic diversity of the A. alba population is still increasing in the Mekong Delta 3 decades after the end of the Vietnam War, but is reaching an asymptotic level that is comparable to the adjacent non-affected... |
Tipo: Text |
Palavras-chave: Agent Orange; Deforestation; Mangrove; Local extinction; Demographic recovery; Genetic recovery; Recolonization genetics. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6898.pdf |
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Teixeira, Sara; Olu, Karine; Decker, Carole; Cunha, Regina L.; Fuchs, Sandra; Hourdez, Stephane; Serrao, Ester A.; Arnaud-haond, Sophie. |
Chemosynthetic ecosystems are distributed worldwide in fragmented habitats harbouring seemingly highly specialized communities. Yet, shared taxa have been reported from highly distant chemosynthetic communities. These habitats are distributed in distinct biogeographical regions, one of these being the so-called Atlantic Equatorial Belt (AEB). Here, we combined genetic data (COI) from several taxa to assess the possible existence of cryptic or synonymous species and to detect the possible occurrence of contemporary gene flow among populations of chemosynthetic species located on both sides of the Atlantic. Several Evolutionary Significant Units (ESUs) of Alvinocarididae shrimp and Vesicomyidae bivalves were found to be shared across seeps of the AEB. Some... |
Tipo: Text |
Palavras-chave: Atlantic equatorial belt; Chemosynthetic habitats; Deep-sea connectivity; Endemic bivalves; Endemic shrimp; Genetic diversity; Microsatellite markers; Mitochondrial COI gene. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00157/26789/24950.pdf |
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Arnaud-haond, Sophie; Duarte, Carlos M.; Diaz-almela, Elena; Marba, Nuria; Sintes, Tomas; Serrao, Ester A.. |
The maximum size and age that clonal organisms can reach remains poorly known, although we do know that the largest natural clones can extend over hundreds or thousands of metres and potentially live for centuries. We made a review of findings to date, which reveal that the maximum clone age and size estimates reported in the literature are typically limited by the scale of sampling, and may grossly underestimate the maximum age and size of clonal organisms. A case study presented here shows the occurrence of clones of slow-growing marine angiosperm Posidonia oceanica at spatial scales ranging from metres to hundreds of kilometres, using microsatellites on 1544 sampling units from a total of 40 locations across the Mediterranean Sea. This analysis revealed... |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00076/18710/16283.pdf |
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Aires, Tania; Serrao, Ester A.; Kendrick, Gary; Duarte, Carlos M.; Arnaud-haond, Sophie. |
Biological invasions rank amongst the most deleterious components of global change inducing alterations from genes to ecosystems. The genetic characteristics of introduced pools of individuals greatly influence the capacity of introduced species to establish and expand. The recently demonstrated heritability of microbial communities associated to individual genotypes of primary producers makes them a potentially essential element of the evolution and adaptability of their hosts. Here, we characterized the bacterial communities associated to native and non-native populations of the marine green macroalga Caulerpa racemosa through pyrosequencing, and explored their potential role on the strikingly invasive trajectory of their host in the Mediterranean. The... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00157/26791/24886.pdf |
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Arnaud-haond, Sophie; Candeias, Rui; Serrao, Ester A.; Teixeira, Sara. |
Polymorphic microsatellites were developed for the invasive green algae Caulerpa taxifolia using next generation DNA sequencing. Results showed a limited rate of microsatellites for the amount of sequences, possibly explaining failure of previous attempts for microsatellite development through classical methods. Eight polymorphic loci were selected that exhibited polymorphism and a null or negligible rate of amplification failure. The number of alleles per locus ranged from two to seven. The reconstruction of Multi Locus Genotypes and the heterozygosity and departure from Hardy-Weinberg equilibrium confirmed the influence of clonal reproduction and showed the usefulness of this set of markers to successfully discriminate clonal lineages and analyze the... |
Tipo: Text |
Palavras-chave: Caulerpa taxifolia; Algae; Invasion; Mediterranean; Queensland; New South Wales; Seagrass. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00126/23720/21598.pdf |
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Ruela Boavida, Joana; Assis, Jorge; Silva, Inga; Serrao, Ester A.. |
Factors shaping the distribution of mesophotic octocorals (30-200 m depth) remain poorly understood, potentially leaving overlooked coral areas, particularly near their bathymetric and geographic distributional limits. Yet, detailed knowledge about habitat requirements is crucial for conservation of sensitive gorgonians. Here we use Ecological Niche Modelling (ENM) relating thirteen environmental predictors and a highly comprehensive presence dataset, enhanced by SCUBA diving surveys, to investigate the suitable habitat of an important structuring species, Paramuricea clavata, throughout its distribution (Mediterranean and adjacent Atlantic). Models showed that temperature (11.5-25.5 degrees C) and slope are the most important predictors carving the niche... |
Tipo: Text |
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Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00359/47003/46932.pdf |
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Teixeira, Sara; Serrao, Ester A.; Arnaud, Sophie. |
Dispersal plays a fundamental role in the evolution and persistence of species, and especially for species inhabiting extreme, ephemeral and highly fragmented habitats as hydrothermal vents. The Mid-Atlantic Ridge endemic shrimp species Rimicaris exoculata was studied using microsatellite markers to infer connectivity along the 7100-Km range encompassing the sampled sites. Astonishingly, no genetic differentiation was found between individuals from the different geographic origins, supporting a scenario of widespread large-scale dispersal despite the habitat distance and fragmentation. We hypothesize that delayed metamorphosis associated to temperature differences or even active directed migration dependent on physical and/or chemical stimuli could explain... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19858/17509.pdf |
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Teixeira, Sara; Cambon-bonavita, Marie-anne; Serrao, Ester A.; Desbruyeres, Daniel; Arnaud-haond, Sophie. |
Aim Deep-sea hydrothermal vents are unstable habitats that are both spatially and temporally fragmented. In vent species, a 'short-term insurance' hypothesis would lead us to expect mostly self-recruitment, limiting the loss of larvae in the deep ocean or water column and increasing genetic differentiation over the time elapsed since colonization. Alternatively, a 'long-term insurance' hypothesis would support the prediction of selection for large-scale dispersal, to ensure long-term persistence in these ephemeral habitats. The main goal of this study was to infer the spatial and temporal distribution of genetic diversity of the shrimp Rimicaris exoculata, which forms high-density local populations on hydrothermal vents along the Mid-Atlantic ridge.... |
Tipo: Text |
Palavras-chave: Bottleneck; Deep-sea biogeography; Dispersal; Genetic diversity; Hydrothermal vents; Marine biogeography; Mid-Atlantic Ridge; Rimicaris exoculata; Spatio-temporal distribution. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00033/14394/12350.pdf |
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Aires, Tania; Marba, Nuria; Serrao, Ester A.; Duarte, Carlos M.; Arnaud-haond, Sophie. |
Molecular analyses of bacteria associated with photosynthetic organisms are often confounded by coamplification of the chloroplastidial 16S rDNA with the targeted bacterial 16S rDNA. This major problem has hampered progress in the characterization of bacterial communities associated to photosynthetic organisms and has limited the full realization of the potential offered by the last generation of metagenomics approaches. A simple and inexpensive method is presented, based on ethanol and bleach treatments prior to extraction, to efficiently discard a great part of chloroplastidial DNA without affecting the characterization of bacterial communities through pyrosequencing. Its effectiveness for the description of bacterial lineages associated to the green... |
Tipo: Text |
Palavras-chave: 16S; Chloroplasts; Elimination; Green algae; Metagenomics. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00076/18739/16464.pdf |
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Moalic, Yann; Arnaud, Sophie; Perrin, Cecile; Pearson, Gareth A.; Serrao, Ester A.. |
Background: Hybridization or divergence between sympatric sister species provides a natural laboratory to study speciation processes. The shared polymorphism in sister species may either be ancestral or derive from hybridization, and the accuracy of analytic methods used thus far to derive convincing evidence for the occurrence of present day hybridization is largely debated. Results: Here we propose the application of network analysis to test for the occurrence of present day hybridization between the two species of brown algae Fucus spiralis and F. vesiculosus. Individual-centered networks were analyzed on the basis of microsatellite genotypes from North Africa to the Pacific American coast, through the North Atlantic. Two genetic distances integrating... |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14600/11921.pdf |
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Registros recuperados: 18 | |
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