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Registros recuperados: 23 | |
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Chomérat, Nicolas; Bilien, Gwenael; Zentz, Frédéric. |
About 30 benthic Prorocentrum species have been described, some of which producing okadaic acid and derivatives involved in diarrhetic shellfish poisoning. The western Caribbean has been extensively studied for benthic dinoflagellates associated with ciguatera, and fifteen Prorocentrum species were described from mangroves and coral reefs of Belize. In contrast, no study reported the diversity of this genus in the Eastern Caribbean, especially in the Lesser Antilles. This study adds to the biodiversity knowledge in Martinique Island by investigating one site of the Caribbean coast from 2010 to 2017. Sediment samples were collected each year in March and studied taxonomically. Identification was realized morphologically by scanning electron microscopy,... |
Tipo: Text |
Palavras-chave: Caribbean; Dinoflagellates; LSU rDNA; Phylogeny; Prorocentrum; Taxonomy. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00469/58075/60483.pdf |
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Sosa, Silvio; Pelin, Marco; Cavion, Federica; Herve, Fabienne; Hess, Philipp; Tubaro, Aurelia. |
Pinnatoxin G (PnTx-G) is a marine cyclic imine toxin produced by the dinoflagellate Vulcanodinium rugosum, frequently detected in edible shellfish from Ingril Lagoon (France). As other pinnatoxins, to date, no human poisonings ascribed to consumption of PnTx-G contaminated seafood have been reported, despite its potent antagonism at nicotinic acetylcholine receptors and its high and fast-acting toxicity after intraperitoneal or oral administration in mice. The hazard characterization of PnTx-G by oral exposure is limited to a single acute toxicity study recording lethality and clinical signs in non-fasted mice treated by gavage or through voluntary food ingestion, which showed differences in PnTx-G toxic potency. Thus, an acute toxicity study was carried... |
Tipo: Text |
Palavras-chave: Vulcanodinium rugosum; Pinnatoxin G; Dinoflagellates; Harmful algae; Oral toxicity. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00605/71724/70190.pdf |
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Zendong, Suzie Zita; Kadiri, Medina; Herrenknecht, Christine; Nezan, Elisabeth; Mazzeo, Antonia; Hess, Philipp. |
Algal toxins may accumulate in fish and shellfish and thus cause poisoning in consumers of seafood. Such toxins and the algae producing them are regularly surveyed in many countries, including Europe, North America, Japan and others. However, very little is known regards the occurrence of such algae and their toxins in most African countries. This paper reports on a survey of phytoplankton and algal toxins in Nigerian coastal waters. Seawater samples were obtained from four sites for phytoplankton identification, on three occasions between the middle of October 2014 and the end of February 2015 (Bar Beach and Lekki in Lagos State, Port Harcourt in Rivers State and Uyo in Akwa Ibom State). The phytoplankton community was generally dominated by diatoms and... |
Tipo: Text |
Palavras-chave: Dinoflagellates; Dinophysis; Phycotoxins; Untargeted analysis; Phytoplankton. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00314/42521/41893.pdf |
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Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle. |
Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic... |
Tipo: Text |
Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf |
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Labry, Claire; Erard-le Denn, Evelyne; Chapelle, Annie; Fauchot, Juliette; Youenou, Agnes; Crassous, Marie-pierre; Le Grand, Jacqueline; Lorgeoux, Benedicte. |
The understanding of the dominance of one species with respect to others is a pertinent challenge in HAB growth dynamics studies and the nutrient supply mode is one of the factors potentially involved. The competition for phosphorus (P) between a toxic species, Alexandrium minutum, and a non-toxic species, Heterocapsa triquetra, was studied (1) along a gradient of P depletion, (2) testing different P depletion degrees before a single PO4 supply and (3) experimenting different PO4 supply frequencies. In conditions Of PO4 depletion, H. triquetra stopped growing after two days both in monospecific and mixed batch cultures whereas A. minutum grew progressively from day 2 until the end of the experiment. This time-lag growth of A. minutum is associated to its... |
Tipo: Text |
Palavras-chave: Semi continuous culture; Batch culture; Ecophysiology; Pulse; Phosphorus storage; Dinoflagellates; Heterocapsa triquetra; Alexandrium minutum. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4067.pdf |
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Sun, Aimei; Li, Chao; Lan, Dongzhao; Zhu, Yue. |
Thirty species of dinoflagellate cysts in 15 genus are identified from KMZK5 Core samples of recent marine sediment at the Luoyuan Bay mouth, Fujian. All of these dinoflagellate cysts are first recorded in the Luyuan Bay, 12 species of them are not distributing in the near sea area such as Sansha Bay and Minjiang estuary, including 6 kinds of toxic species, such as Alexandrium affine,A. minutum, A. tamarense, Gonyaulax spinifera, Gymnodinium catenatum and Scrippsiella trochoidea. The abundance and vertical distribution characterestics of the main and the toxic dinoflgellate cysts are also studied in the paper. |
Tipo: Journal Contribution |
Palavras-chave: Vertical distribution; Toxicity; Dinoflagellates. |
Ano: 2007 |
URL: http://hdl.handle.net/1834/5837 |
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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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Klouch, Khadidja; Schmidt, Sabine; Andrieux-loyer, Francoise; Le Gac, Mickael; Hervio-heath, Dominique; Qui-minet, Zujaila Nohemi; Quere, Julien; Bigeard, Estelle; Guillou, Laure; Siano, Raffaele. |
The multiannual dynamic of the cyst-forming and toxic marine dinoflagellate Alexandrium minutum was studied over a time scale of about 150 years by a paleoecological approach based on ancient DNA (aDNA) quantification and cyst revivification data obtained from two dated sediment cores of the Bay of Brest (Brittany, France). The first genetic traces of the species presence in the study area dated back to 1873 ± 6. Specific aDNA could be quantified by a newly-developed real-time PCR assay in the upper core layers, in which the germination of the species (in up to 17–19 year-old sediments) was also obtained. In both cores studied, our quantitative paleogenetic data showed a statistically significant increasing trend in the abundance of A. minutum ITS1 rDNA... |
Tipo: Text |
Palavras-chave: Paleoecology; Ancient DNA; Real-time PCR; Harmful algal blooms (HAB); Dinoflagellates; Coastal ecology. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44516/44212.pdf |
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Carlsoon, Per; Edling, Hélène; Bechemin, Christian. |
Dissolved organic matter in the form of riverine humic substances stimulated the growth of both axenic nitrogen-limited Alexandrium catenella cultures and nitrogen-limited cultures with a marine bacterial community present. The biomass increase of A. catenella could not be accounted for by utilization of inorganic nitrogen compounds. However, there was a considerable release of dissolved free and combined amino acids from the humic substances that was utilized by A. catenella. About 40% of the nitrogen used by A. catenella in the axenic treatment with humic substances added was taken up as organic nitrogen. Bacterial aminopeptidase and beta -glucosidase activity was stimulated by the addition of humic substances and bacterial growth increased several-fold.... |
Tipo: Text |
Palavras-chave: Alexandrium catenella; Dinoflagellates; Bacteria; DOM; Humic substances. |
Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/00173/28431/26763.pdf |
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Christaki, Urania; Georges, Clement; Genitsaris, Savvas; Monchy, Sebastien. |
The spatial and temporal community composition of microzooplankton (dinoflagellates and ciliates) was assessed in the Kerguelen area (Southern Ocean) during the KEOPS2 cruise in early spring (October-November) 2011. This naturally iron-fertilized region was characterized by a complex mesoscale circulation resulting in a patchy distribution of phytoplankton blooms. Collectively, 97 morphospecies of dinoflagellates and ciliates belonging to 41 genera were identified by microscopy, and 202 Alveolata-related OTUs (operational taxonomical units) were retrieved with tag-pyrosequencing. Microscopy and pyrosequencing data were in accordance, in that diatom-consuming dinoflagellates were the most enhanced taxa in the blooms. Dinoflagellates also showed significant... |
Tipo: Text |
Palavras-chave: Dinoflagellates; Ciliates; Natural iron fertilization; Southern Ocean. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00351/46255/46080.pdf |
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Chomerat, Nicolas; Sellos, Daniel Y.; Zentz, Frederic; Nezan, Elisabeth. |
A new marine benthic Prorocentrum species from sandy habitats of South Brittany (northwestern France), P. consutum sp. nov., is described using LM and SEM and molecular phylogenetic analyses. Cells have a subcircular to broadly ovoid shape and are plainly flattened. They are 57-61 lm long and 52-55 lm wide. A central pyrenoid is present, and the kidney-shaped nucleus is positioned in the posterior region. In right valve view, the periflagellar area is deeply excavated, and the left valve forms a prominent apical ridge. The periflagellar area consists of nine platelets, and a small narrow collar is present around the flagellar pore. The ornamentation of this new species is very peculiar and is characterized by a ring of round areolae located at the... |
Tipo: Text |
Palavras-chave: Taxonomy; SSU rDNA; SEM; Prorocentrum; Nuclear DNA; Molecular phylogeny; LSU rDNA; Dinoflagellates. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2010/publication-7449.pdf |
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NAVARRO,JORGE M; CONTRERAS,ANDREA M; CHAPARRO,ÓSCAR R. |
The short-term feeding response of the bivalve Mytilus chilensis was measured using four diets containing different proportions of the toxic dinoflagellate Alexandrium catenella. The diets containing the highest concentrations of the dinoflagellate showed the greatest effect on the feeding activity in the mussel, with clearance and ingestión rates significantly reduced during the first hours of exposure. After this period, M. chilensis demonstrated a capacity to acclimate to the toxic diets, with feeding parameters reaching values similar to those of untreated control organisms. It was not clear if the negative effect on the feeding behavior was caused by the presence of the paralytic toxin, or due to the larger size of the dinoflagellate cells in... |
Tipo: Journal article |
Palavras-chave: Mytilus chilensis; Feeding response; PSP; Dinoflagellates. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2008000100004 |
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Hameed, Hameed A.; Saburova, Maria; Chomérat, Nicolas. |
Background The occurrence of a small brackish water bloom-forming dinoflagellate belonging to the genus Peridiniopsis is reported for the first time from the Shatt Al-Arab River in Iraq. Based on the study of cell morphology, this taxon was attributed to the recently described Peridiniopsis minima, recorded so far only from the Jiulongjiang River, China. Results The description of P. minima was extended to include some previously unreported details of the thecal surface, apical pore complex, and sulcus structure using light and scanning electron microscopy. Cells of this species from Iraq were oval to rhombic in shape and slightly dorso-ventrally compressed, with distinct red eyespot and endosymbiont nucleus. Cells were covered by a thin theca with the... |
Tipo: Text |
Palavras-chave: Dinophyceae; Dinoflagellates; Iraq; Morphology; Peridiniopsis; Shatt Al-Arab River; Taxonomy; SEM. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00664/77594/79608.pdf |
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Registros recuperados: 23 | |
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