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Registros recuperados: 30
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Adding new pieces to the Azadinium (Dinophyceae) diversity and biogeography puzzle: Non-toxigenic Azadinium zhuanum sp. nov. from China, toxigenic A. poporum from the Mediterranean, and a non-toxigenic A. dalianense from the French Atlantic ArchiMer
Luo, Zhaohe; Krock, Bernd; Mertens, Kenneth; Nezan, Elisabeth; Chomerat, Nicolas; Bilien, Gwenael; Tillmann, Urban; Gu, Haifeng.
The marine planktonic dinophyceaen genus Azadinium is a primary source of azaspiracids, but due to their small size its diversity may be underestimated and information on its biogeography is still limited. A new Azadinium species, A. zhuanum was obtained from the East China Sea and Yellow Sea of China by incubating surface sediments. Five strains were established by isolating single germinated cells and their morphology was examined with light microscopy and scanning electron microscopy. Azadinium zhuanum was characterized by a plate pattern of Po, cp, X, 4′, 2a, 6′′, 6C, 5S, 6′′′, 2′′′′, by a distinct ventral pore at the junction of Po, the first and fourth apical plates, and a conspicuous antapical spine. Moreover, Azadinium poporum was obtained for the...
Tipo: Text Palavras-chave: Azadinium; Azaspiracid; AZA-2; AZA-2 phosphate; Biogeography; China; French Atlantic; Mediterranean Sea.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00386/49765/51155.pdf
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Algal toxin profiles in Nigerian coastal waters (Gulf of Guinea) using passive sampling and liquid chromatography coupled to mass spectrometry ArchiMer
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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Cabra reticulata sp. nov. (Dinophyceae), a new sand-dwelling dinoflagellate from the Atlantic Ocean ArchiMer
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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Chaetoceros armatum - Diatomée de la zone de ressac, vecteur d'efflorescences colorées hivernales - Cas de la Baie d'Audierne, plage de Tronoën ArchiMer
Le Gal, Dominique; Nezan, Elisabeth; Raguenes, Pierre; Piclet, Guy.
Dans le cadre du Réseau de surveillance phytoplanctonique, nous nous sommes intéressés à un phénomène particulier d'eaux colorées. L'espèce responsable Chaetoceros armatum a fait l'objet d'un suivi sur plusieurs mois et les résultats exposés dans ce rapport concernent essentiellement la période février 1992 à mars 1993. Nous nous limiterons à présenter cette espèce particulière pour laquelle la bibliographie est assez pauvre, et à décrire le phénomène in situ.
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Ano: 1995 URL: http://archimer.ifremer.fr/doc/00017/12806/9749.pdf
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Description and phylogenetic position of Plagiolemma distortum sp. nov., a new raphid diatom (Bacillariophyceae) from French coastal waters ArchiMer
Nezan, Elisabeth; Bilien, Gwenael; Boulben, Sylviane; Mertens, Kenneth; Chomerat, Nicolas.
A new marine raphid diatom, Plagiolemma distortum Nézan, sp. nov. is described from plankton samples from the Atlantic Ocean, south Brittany (north-western France), where it was regularly observed, but never in high abundances. Cells have an unusual and complex shape under light microscopy (LM) depending on their position and orientation. The two valves are highly vaulted and narrow in width (transapical axis). Cells contain four complexly lobed plastids and a variable number of refractive granules without particular localization. In addition, capsules containing motile cells were observed. Ultrastructural details of the frustules were investigated using scanning electron microscopy (SEM). The girdle bands are simple. Each valve possesses a sigmoid raphe...
Tipo: Text Palavras-chave: Capsules; Habitat; Molecular phylogeny; Plastids; Raphid diatom; Video.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00441/55235/56797.pdf
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Dynamics of phytoplankton communities in eutrophying tropical shrimp ponds affected by vibriosis ArchiMer
Lemonnier, Hugues; Lantoine, Francois; Courties, Claude; Guillebault, Delphine; Nezan, Elisabeth; Chomerat, Nicolas; Escoubeyrou, Karine; Galinie, Christian; Blockmans, Bernard; Laugier, Thierry.
Tropical shrimp aquaculture systems in New Caledonia regularly face major crises resulting from outbreaks of Vibrio infections. Ponds are highly dynamic and challenging environments and display a wide range of trophic conditions. In farms affected by vibriosis, phytoplankton biomass and composition are highly variable. These conditions may promote the development of harmful algae increasing shrimp susceptibility to bacterial infections. Phytoplankton compartment before and during mortality outbreaks was monitored at a shrimp farm that has been regularly and highly impacted by these diseases. Combining information from flow cytometry, microscopy, pigment and phylogenetic analysis, the presence of Picocyanobacteria, Prasinophyceae and Diatomophyceae were...
Tipo: Text Palavras-chave: Tropical aquaculture pond; Litopenaeus stylirostris; Vibriosis; Eutrophication; Phytoplankton; Harmful algae.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00343/45411/44986.pdf
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DYNAPSE - DYNamiques des efflorescences et de la toxicité des espèces phytoplanctoniques nuisibles du genre PSEudo nitzschia en région Loire Bretagne ArchiMer
Belin, Catherine; Chapelle, Annie; Delmas, Daniel; Nezan, Elisabeth; Siano, Raffaele.
Les efflorescences de la diatomée Pseudo-nitzschia sont largement répandues sur les côtes Manche-Atlantique depuis une trentaine d’années (source Rephy). Depuis les années 2000 elles y sont parfois associées des événements toxiques du type ASP (Amnesic Shellfish Poisonning) qui perturbent grandement les pêcheries de coquillages et notamment celles de coquilles Saint Jacques. Les efflorescences et toxicités liées aux Pseudo-nitzschia sont des phénomènes en augmentation sur les côtes françaises mais aussi mondialement. Le genre Pseudo-nitzschia comprend plusieurs espèces très difficiles à identifier en routine or certaines sont toxiques et d’autres pas. Les facteurs environnementaux abiotiques et biotiques contrôlent à la fois la croissance des microalgues...
Tipo: Text Palavras-chave: Algues toxiques; Pseudo nitzschia; Toxicité des coquillages; Pêcheries; Facteurs environnementaux.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00189/30035/28521.pdf
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First record of resting cysts of the benthic dinoflagellate Prorocentrum leve in a natural reservoir in Gujan-Mestras, Gironde, France ArchiMer
Mertens, Kenneth; Gu, Haifeng; Pospelova, Vera; Chomerat, Nicolas; Nezan, Elisabeth; Gurdebeke, Pieter; Bogus, Kara; Vrielinck, Henk; Rumebe, Myriam; Meteigner, Claire.
The resting cysts of the benthic dinoflagellate Prorocentrum leve from a natural reservoir in Gujan-Mestras (Gironde, France) were described in this study. The incubated urn-shaped cysts gave rise to cells of Prorocentrum leve. Morphological observations through light microscopy and scanning electron microscopy, particularly of the periflagellar platelets, combined with large subunit ribosomal DNA sequences obtained through single-cell analysis confirm their affinity to the species Prorocentrum leve. The cysts are characterized by a specific shape and the presence of an anterior plug. This is the first conclusive evidence for fossilizable resting stages within the Prorocentrales, one of the major orders within the Dinophyceae. Palynological treatments show...
Tipo: Text Palavras-chave: Cellulosic; Micro-FTIR; Palynology; Prorocentrales; Resting stage.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00398/50971/51728.pdf
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First record of the genus Azadinium (Dinophyceae) from the Shetland Islands, including the description of Azadinium polongum sp. nov. ArchiMer
Tillmann, Urban; Soehner, Sylvia; Nezan, Elisabeth; Krock, Bernd.
Azadinium is a dinophycean genus capable of producing azaspiracids (AZAs), a recently discovered group of lipophilic phycotoxins causing human intoxication via mussel consumption. Although initially described from the North Sea, the genus currently consisting of four described species is probably distributed worldwide. Here we report on Azadinium from the Shetland Islands, which are located in the northernmost part of the North Sea and are largely influenced by the Atlantic Ocean. Two strains of Azadinium were isolated from a single water sample. One strain was identified as Azadinium spinosum based on morphology and sequence data and had an AZA cell quota of about 20 fg per cell, similar to all other described strains of the species. The toxin profile...
Tipo: Text Palavras-chave: Azadinium; Azaspiracids; New species; Shetland Islands.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00108/21963/20691.pdf
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Fragilidium duplocampanaeforme sp nov (Dinophyceae): A new phagotrophic dinoflagellate from the French Atlantic coast ArchiMer
Nezan, Elisabeth; Chomerat, Nicolas.
A new species of the genus Fragilidium, F. duplocampanaeforme sp. nov., is described from examinations by LM and SEM. This species has been recorded in summer on the French Atlantic coast, over a number of years. It was never abundant in the plankton and was very often associated with Fragilidium subglobosum, Pyrophacus horologium and also with toxigenic species of the genera Alexandrium and Dinophysis. Phagotrophy of F. duplocampanaeforme on Dinophysis prey is shown, and sexual reproduction is suggested by the observation of gamete-like small forms. The size and the peculiar shape of its cells do not correspond to any known taxon, but the plate arrangement fits the genus Fragilidium. The plate formula is Po, Pc, 4', 8 '', 10c, 6s?, 7"', 2 '''', lp. A...
Tipo: Text Palavras-chave: Taxonomy; Phagotrophy; Fragilidium duplocampanaeforme sp nov.; Fragilidium; Dinophyceae; Atlantic ocean.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6233.pdf
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Genetic diversity of the harmful family Kareniaceae (Gymnodiniales, Dinophyceae) in France, with the description of Karlodinium gentienii sp. nov.: A new potentially toxic dinoflagellate ArchiMer
Nezan, Elisabeth; Siano, Raffaele; Boulben, Sylviane; Six, Christophe; Bilien, Gwenael; Cheze, Karine; Duval, Audrey; Le Panse, Sophie; Quere, Julien; Chomerat, Nicolas.
The family Kareniaceae is mostly known in France for recurrent blooms of Karenia mikimotoi in the Atlantic, English Channel, and Mediterranean Sea and for the unusual green discoloration in the saltwater lagoon of Diana (Corsica) caused by Karlodinium corsicum in April 1994. In terms of diversity, this taxonomic group was long overlooked owing to the difficult identification of these small unarmored dinoflagellates. In this study, thanks to the molecular characterization performed on single cells from field samples and cultures, twelve taxonomic units were assigned to the known genera Karenia, Karlodinium and Takayama, whereas one could not be affiliated to any described genus. The molecular phylogeny inferred from the D1–D2 region of the LSU rDNA showed...
Tipo: Text Palavras-chave: Genetic diversity; Haemolytic; Kareniaceae; Pigments; Single cell; Taxonomy.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00225/33611/32310.pdf
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Growth anomalies in Pecten maximus from coastal waters (Bay of Brest, France): relationship with diatom blooms ArchiMer
Lorrain, Anne; Paulet, Yves-marie; Chauvaud, Laurent; Savoye, Nicolas; Nezan, Elisabeth; Guerin, Laurent.
The aim of this study was to characterize the daily shell growth of Pecten maximus from early 1998 to late spring 1999 in the Bay of Brest with a careful qualitative and quantitative description of the pelagic primary production. Our results, in accordance with previous studies, demonstrate that there are episodic declines in the growth rate. Concurrent events of low growth rate and large bottom-concentrations of algae following diatom blooms (Cerataulina pelagica or Rhizosolenia delicatula), suggests that this high concentration of phytoplankton on the bottom layer may affect food intake or respiratory activity of the scallops by gill clogging or oxygen depletion. In this study, silicic acid or phosphorus are inferred to be limiting factors responsible...
Tipo: Text Palavras-chave: Biscay bay; Limiting factors; Primary production; Phytoplankton cnoncentration; Pecten maximus; Growth rate.
Ano: 2000 URL: http://archimer.ifremer.fr/doc/2000/publication-612.pdf
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Guide pratique à l'usage des analystes du Réseau National de Surveillance du phytoplancton ArchiMer
Nezan, Elisabeth; Piclet, Guy; Grossel, Hubert.
This work is based on optical microscopic photographs. It helps to the identification of the phytoplanktonic organisms from the french coastal zones and to the normalization of the results of microscopic analysis. 1)Dinophyceae and dinoflagellate 2)Bacillariophyceae or diatomophyceae,named diatoms 3)Others classes
Tipo: Text Palavras-chave: Dinoflagellate; Diatoms; France; Coastal zones; Identification; Phytoplankton.
Ano: 1997 URL: https://archimer.ifremer.fr/doc/00502/61382/65020.pdf
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Identification of Pseudo-nitzschia australis and P. multiseries in the Bay of Seine. Was there a relation to presence of domoic acid in king scallops in autumn 2004? ArchiMer
Nezan, Elisabeth; Antoine, Elisabeth; Fiant, Liliane; Billard, C.
In late 2004, the French phytoplankton monitoring network (REPHY of Ifremer) detected domoic acid (DA) above the EU-regulatory limit of 20 μg DA/g tissue in king scallops (Pecten maximus) from the Bay of Seine in the Channel (Fig. 1). Shellfish harvesting sites were closed for several months due to slow depuration of the scallops.
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Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-6331.pdf
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Impact de la pisciculture marine intensive sur l'environnement : (2) l'environnement d'un site d'élevage de salmonidés en cages flottantes, Camaret année 1994 ArchiMer
Kempf, Marc; Jacq, E; Le Guellec, C; Merceron, Michel; Monfort, Patrick; Nezan, Elisabeth; Ryckaert, Mireille.
This document presents a year-long (1994) environmental study conducted on a site of intensive farming of salmonids (mainly fario trout) in Camaret Bay. A set of parameters were considered for the body of water and the sea bed (flow patterns, hydrology, sedimentology, biology, chemistry) and complemented by video observations. The study concluded that there was a measurable effect from the farm in its current configuration, but that the impact was of a very limited intensity and scope that did not affect the environment in a substantial way. It is recommended that production growth be accompanied by a minimum amount of environmental assessment.
Tipo: Text Palavras-chave: Bretagne; Truite fario; Salmonidés; Environnement; Pisciculture marine.
Ano: 1995 URL: http://archimer.ifremer.fr/doc/1995/rapport-2834.pdf
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Inter and intra-specific growth and domoic acid production in relation to nutrient ratios and concentrations in Pseudo-nitzschia : phosphate an important factor ArchiMer
Lema, Anais Kimberley; Latimier, Marie; Nezan, Elisabeth; Fauchot, Juliette; Le Gac, Mickael.
The factors responsible for inducing the synthesis of toxins and responses from toxic phytoplankton blooms remain unclear. In this study we compare the influence of genotypic (at both the intra and interspecific levels) and environmental factors (nutrient concentration and ratio) on growth (in terms of cell densities) and domoic acid (DA) production in three Pseudo-nitzschia species: P. australis, P.pungens and P.fradulenta. A strong phosphate effect was detected. More precisely, a low initial concentration in phosphate, even at high initial nitrogen and silicate concentrations, induced the highest DA concentrations and the lowest cell densities in all strains/species studied. In contrast, a low initial concentration of nitrogen and silicate combined, with...
Tipo: Text Palavras-chave: Pseudo-nitzschia strains; Domoic acid; Ratio; Phosphate; Nitrogen.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00377/48849/49397.pdf
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Micro-algues des claires ostréicoles de Charente Maritime : focus sur les producteurs potentiels de toxines DSP, PSP et ASP et toxines émergentes (palytoxines, pinnatoxine...) ArchiMer
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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Micro-algues toxiques et nuisibles de l’océan mondial. COI Manuels et Guides, 68 ArchiMer
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.
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Ano: 2016 URL: https://archimer.ifremer.fr/doc/00379/49054/49508.pdf
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Morphological and Molecular Characterisation of Three New Azadinium Species (Amphidomataceae, Dinophyceae) from the Irminger Sea ArchiMer
Tillmann, Urban; Gottschling, Marc; Nezan, Elisabeth; Krock, Bernd; Bilien, Gwenael.
Some species of the planktonic dinoflagellate genus Azadinium produce azaspiracids (AZAs), a group of lipophilic phycotoxins causing human poisoning after mussel consumption. We describe three new species from the North Atlantic, all of which shared the same Kofoidean plate pattern characteristic for Azadinium: Po, cp, X, 4′, 3a, 6′́, 6 C, 5S, 6′́́, 2′́́́. Azadinium trinitatum sp. nov. was mainly characterized by the presence of an antapical spine and by the position of the ventral pore at the left distal end of the pore plate in a cavity of Plate 1′ Plate 1. Azadinium cuneatum sp. nov. had a conspicuously formed first apical plate, which was asymmetrically elongated and tapered on its left lateral side with a ventral pore located at the tip of this...
Tipo: Text Palavras-chave: Azadinium; Azaspiracids; Irminger Sea; Iceland; New species.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00188/29917/28382.pdf
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Morphology and molecular phylogeny of prorocentrum consutum sp. nov. (dinophyceae), a new benthic dinoflagellate from south Brittany (northwestern France) ArchiMer
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
Registros recuperados: 30
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