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| Registros recuperados: 30 | |
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| Brissard, Charline; Herrenknecht, Christine; Sechet, Veronique; Herve, Fabienne; Pisapia, Francesco; Harcouet, Jocelyn; Lemee, Rodolphe; Chomerat, Nicolas; Hess, Philipp; Amzil, Zouher. |
| Ostreopsis cf. ovata produces palytoxin analogues including ovatoxins (OVTXs) and a putative palytoxin (p-PLTX), which can accumulate in marine organisms and may possibly lead to food intoxication. However, purified ovatoxins are not widely available and their toxicities are still unknown. The aim of this study was to improve understanding of the ecophysiology of Ostreopsis cf. ovata and its toxin production as well as to optimize the purification process for ovatoxin. During Ostreopsis blooms in 2011 and 2012 in Villefranche-sur-Mer (France, NW Mediterranean Sea), microalgae epiphytic cells and marine organisms were collected and analyzed both by LC-MS/MS and hemolysis assay. Results obtained with these two methods were comparable, suggesting ovatoxins... |
| Tipo: Text |
Palavras-chave: Ostreopsis cf. ovata; Palytoxin & ovatoxins; Culture; Seafood contamination; LC-MS/MS; Hemolysis assay; Mediterranean Sea. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00199/31025/29428.pdf |
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| Le Gac, Mickael; Metegnier, Gabriel; Chomerat, Nicolas; Malestroit, Pascale; Quere, Julien; Bouchez, Olivier; Siano, Raffaele; Destombe, Christophe; Guillou, Laure; Chapelle, Annie. |
| Understanding divergence in the highly dispersive and seemingly homogeneous pelagic environment for organisms living as free drifters in the water column remains a challenge. Here, we analyzed the transcriptome wide mRNA sequences, as well as the morphology of 18 strains of Alexandrium minutum, a dinoflagellate responsible for Harmful Algal Blooms worldwide, to investigate the functional bases of a divergence event. Analysis of the joint site frequency spectrum (JSFS) pointed toward an ancestral divergence in complete isolations followed by a secondary contact resulting in gene flow between the two diverging groups, but heterogeneous across sites. The sites displaying fixed SNPs were associated with a highly restricted gene flow and a strong... |
| Tipo: Text |
Palavras-chave: Dinoflagellates; Harmful algal blooms; Populations Genomics; Pseudocryptic species; Speciation. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45857/45529.pdf |
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| Abadie, Eric; Muguet, Alexia; Berteaux, Tom; Chomerat, Nicolas; Hess, Philipp; Roque D'Orbcastel, Emmanuelle; Masseret, Estelle; Laabir, Mohamed. |
| Vulcanodinium rugosum, a recently described species, produces pinnatoxins. The IFR-VRU-01 strain, isolated from a French Mediterranean lagoon in 2010 and identified as the causative dinoflagellate contaminating mussels in the Ingril Lagoon (French Mediterranean) with pinnatoxin-G, was grown in an enriched natural seawater medium. We tested the effect of temperature and salinity on growth, pinnatoxin-G production and chlorophyll a levels of this dinoflagellate. These factors were tested in combinations of five temperatures (15, 20, 25, 30 and 35 °C) and five salinities (20, 25, 30, 35 and 40) at an irradiance of 100 µmol photon m−2 s−1. V. rugosum can grow at temperatures and salinities ranging from 20 °C to 30 °C and 20 to 40, respectively. The optimal... |
| Tipo: Text |
Palavras-chave: Vulcanodinium rugosum; Mediterranean Ingril Lagoon; Toxin production; Growth conditions; Temperature; Salinity. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00333/44429/44095.pdf |
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| Chomerat, Nicolas; Nezan, Elisabeth. |
| A new sand-dwelling dinoflagellate species, Cabra reticulata sp. nov., is described from sandy habitats in the south of Brittany (northwestern France). This new species possesses the characteristics of the 'unusual' genus, Cabra Murray et Patterson. The thecal plate formula is Po Pt 3' 1a 4'' 'x' 3c ?s 5''' 1'''' (or alternatively interpreted as Po Pt 4' 0a 4'' 'x' 3c ?s 5''' 1''''). Because of the strong lateral compression, cells of C. reticulata are frequently seen laterally and have a polygonal shape, with three prominent antapical pointed flanges and a dorsal spine in the anterior part of the hypotheca. The cingulum is ascending and incomplete. The thecal surface is ornamented with strong reticulations forming polygonal areolae, which differs from C.... |
| Tipo: Text |
Palavras-chave: Taxonomy; Sand dwelling; Roscoffia; Protists; Podolampaceae; Marine; Dinophyceae; Benthic. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6804.pdf |
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| Mertens, Kenneth; Chomerat, Nicolas; Nezan, Elisabeth; Bruneau, Audrey; Le Bec, Claude. |
| Les inspections vétérinaires de la Commission Européenne ayant signifié à la France son constat d'une absence de réserau de surveillance sur les claires ostréicoles, la DGAL a mandaté l'Ifremer afin de réaliser un premier diagnostic sur le phytoplancton. Cette commande de la DGAL place l'Ifremer LERBO comme prestataire de service et spécialiste des micro-algues. Les claires ostréicoles étant hors du domaine public maritime, une concertation avec le Comité Régional de la Conchyliculture de Poitou-Charentes, la DGAL et la DDTM 17 en juin 2018 a permis de proposer six claires, réparties entre l'île de Ré et l'île d'Oléron et pouvant être échantillonnées. L'objectif est de faire un état des lieux de la présence ou de l'absence de cellules de phytoplancton... |
| Tipo: Text |
Palavras-chave: Charentes; Claire; Phytoplancton; Micro-algue; Toxine. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59731/62828.pdf |
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| Lassus, Patrick; Chomerat, Nicolas; Hess, Philipp; Nezan, Elisabeth. |
| This book updates available international databases on toxic and harmful species of phytoplankton and micro-phytobenthos. It lists regional occurrences at world-wide scale: localities, cell densities, toxicity levels in contaminated animals, human and animal poisoning, isolation of identified active molecules and toxins, documentary sources. Finally, this book addresses the geographic distributions of phycotoxin-producers from recent data. The objective is to analyze the evolution of toxic and harmful episodes over the past 30 years to identify trends, and to introduce a discussion on the reality of a time-dependent increase in the number of known species and toxins. |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00379/49054/49508.pdf |
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| Ben-gharbia, Hela; Yahia, Ons Kefi-daly; Amzil, Zouher; Chomerat, Nicolas; Abadie, Eric; Masseret, Estelle; Sibat, Manoella; Triki, Habiba Zmerli; Nouri, Habiba; Laabir, Mohamed. |
| armful benthic dinoflagellates, usually developing in tropical areas, are expanding to temperate ecosystems facing water warming. Reports on harmful benthic species are particularly scarce in the Southern Mediterranean Sea. For the first time, three thermophilic benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima and Coolia monotis) were isolated from Bizerte Bay (Tunisia, Mediterranean) and monoclonal cultures established. The ribotyping confirmed the morphological identification of the three species. Maximum growth rates were 0.59 ± 0.08 d−1 for O. cf. ovata, 0.35 ± 0.01 d−1 for C. monotis and 0.33 ± 0.04 d−1 for P. lima. Toxin analyses revealed the presence of ovatoxin-a and ovatoxin-b in O. cf. ovata cells. Okadaic acid and... |
| Tipo: Text |
Palavras-chave: Ostreopsis cf. ovata; Prorocentrum lima; Coolia monotis; Southern Mediterranean Sea; Growth; Toxicity. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00355/46585/46393.pdf |
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| Coute, Alain; Perrette, Catherine; Chomerat, Nicolas. |
| Clipperton Island is a small French coral atoll in the eastern Pacific Ocean, which has been rarely investigated because of its remote location and difficult access. There is little scientific information on this ecosystem and only a few microalgae have been reported from the lagoon. To date, only one dinoflagellate taxon, Peridiniopsis cristata, is known to inhabit the lagoon. During an expedition in 2005 to study the lagoon and the surrounding oceanic waters of Clipperton Island, a further investigation of the lagoon phytoplankton was undertaken. In addition to P. cristata, which was still abundant in the upper water layer, two other thecate dinoflagellates were recorded. One dinoflagellate was identified as Durinskia baltica, while the other had the... |
| Tipo: Text |
Palavras-chave: Dinoflagellates; Lagoon; Morphology; Phytoplankton; Taxonomy. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00070/18086/15633.pdf |
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| Registros recuperados: 30 | |
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