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| Registros recuperados: 21 | |
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| 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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| 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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| Mertens, Kenneth; Carbonell-moore, Maria Consuelo; Pospeloya, Vera; Head, Martin J.; Highfield, Andrea; Schroeder, Declan; Gu, Haifeng; Andree, Karl B.; Fernandez, Margarita; Yamaguchi, Aika; Takano, Yoshihito; Matsuoka, Kazumi; Nezan, Elisabeth; Bilien, Gwenael; Okolodkov, Yuri; Koike, Kazuhiko; Hoppenrath, Mona; Pfaff, Maya; Pitcher, Grant; Al-muftah, Abdulrahman; Rochon, Andre; Lim, Po Teen; Leaw, Chui Pin; Lim, Zhen Fei; Ellegaard, Marianne. |
| trains of a dinoflagellate from the Salton Sea, previously identified as Protoceratium reticulatum and yessotoxin producing, have been reexamined morphologically and genetically and Pentaplacodinium saltonense n. gen. et sp. is erected to accommodate this species. Pentaplacodinium saltonense differs from Protoceratium reticulatum (Claparède et Lachmann 1859) Bütschli 1885 in the number of precingular plates (five vs. six), cingular displacement (two widths vs. one), and distinct cyst morphology. Incubation experiments (excystment and encystment) show that the resting cyst of Pentaplacodinium saltonense is morphologically most similar to the cyst-defined species Operculodinium israelianum (Rossignol, 1962) Wall (1967) and O. psilatum Wall (1967).... |
| Tipo: Text |
Palavras-chave: Pentaplacodinium; Protoceratium; Precingular plates; Salton Sea; Ceratocorys; Operculodinium; Cribroperidinioideae. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52756/53852.pdf |
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| Monfort, Patrick; Hervio Heath, Dominique; Caprais, Marie-paule; Pommepuy, Monique; Annezo, Jean-pierre; Loaec, Solen; Le Mennec, Cecile; Guillerm, Emmanuelle; Boulben, Sylviane; Bilien, Gwenael; Bonsor, Robert; Porter, Jonathan; Pickup, Roger. |
| Le projet européen Cycleau, initié à l'échelle locale sur la problèmatique de l'envasement et de l'ensablement de l'estuaire du Bélon, y a également intégré un volet bactériologique en raison des contraintes fortes que faisaient peser les pics conjoncturels de contamination sur la profession conchylicole (fermetures temporaires, déclassement éventuel) mais plus largement sur l'image du territoire (impact touristique) et en définitive sur son développement durable. Pour satisfaire la restauration de la qualité des eaux estuariennes, l'IFREMER a fait appel à un certain nombre d'outils susceptibles de contribuer à la formulation d'un diagnostic pertinent et ainsi de répondre aux préoccupations des acteurs du littoral. Pour ce faire, nous avons créé un réseau... |
| Tipo: Text |
Palavras-chave: Bassin versant; Contamination fécale; Escherichia coli; Flux bactériens; Bactériophages; SIG; Évaluation. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00200/31077/29490.pdf |
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| Chomérat, Nicolas; Bilien, Gwenael; Derrien, Amelie; Henry, Kévin; Ung, André; Viallon, Jérôme; Darius, Hélène Taiana; Mahana Iti Gatti, Clémence; Roué, Mélanie; Hervé, Fabienne; Réveillon, Damien; Amzil, Zouher; Chinain, Mireille. |
| To date, the genus Ostreopsis comprises eleven described species, of which seven are toxigenic and produce various compounds presenting a major threat to human and environmental health. The taxonomy of several of these species however remains controversial, as it was based mostly on morphological descriptions leading, in some cases, to ambiguous interpretations and even possible misidentifications. The species Ostreopsis lenticularis was first described by Y. Fukuyo from French Polynesia using light microscopy observations, but without genetic information associated. The present study aims at revisiting the morphology, molecular phylogeny and toxicity of O. lenticularis based on the analysis of 47 strains isolated from 4 distinct locales of French... |
| Tipo: Text |
Palavras-chave: ITS-5.8S rDNA; LSU rDNA; Microscopy; Ostreopsis lenticularis; Taxonomy; Toxins. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59747/62887.pdf |
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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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| Roux, Pauline; Siano, Raffaele; Collin, Karine; Bilien, Gwenael; Sinquin, Corinne; Marchand, Laetitia; Zykwinska, Agata; Delbarre-ladrat, Christine; Schapira, Mathilde. |
| High biomasses of the marine dinoflagellate Lepidodinium chlorophorum cause green seawater discolorations along Southern Brittany (NE Atlantic, France). The viscosity associated to these phenomena has been related to problems in oyster cultivation. The harmful effect of L. chlorophorum might originate from the secretion of Extracellular Polymeric Substances (EPS). To understand whether the EPS are produced by L. chlorophorum or its associated bacteria, or if they are a product of their interaction, batch cultures were performed under non-axenic and pseudo-axenic conditions for three strains. Maximum dinoflagellate cell abundances were observed in pseudo-axenic cultures. The non-sinking fraction of polymers (Soluble Extracellular Polymers, SEP), mainly... |
| Tipo: Text |
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| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79403/81948.pdf |
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| Luo, Zhaohe; Yang, Weidong; Leaw, Chui Pin; Pospelova, Vera; Bilien, Gwenael; Liow, Guat Ru; Lim, Po Teen; Gu, Haifeng. |
| Blooms of the harmful dinoflagellate Akashiwo sanguinea are responsible for the mass mortality of fish and invertebrates in coastal waters. This cosmopolitan species includes several genetically differentiated clades. Four clonal cultures were established by isolating single cells from Xiamen Harbour (the East China Sea) for morphological and genetic analyses. The cultures displayed identical morphology but were genetically different, thus revealing presence of cryptic diversity in the study area. New details of the apical structure complex of Akashiwo sanguinea were also found. To investigate whether the observed cryptic diversity was related to environmental differentiation, 634 cells were obtained from seasonal water samples collected from 2008 to 2012.... |
| Tipo: Text |
Palavras-chave: Biogeography; Cryptic species; Gymnodinium sanguineum; Seasonal occurrence; Speciation. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00386/49771/50355.pdf |
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| Li, Zhun; Mertens, Kenneth; Nézan, Elisabeth; Chomérat, Nicolas; Bilien, Gwenael; Iwataki, Mitsunori; Shin, Hyeon Ho. |
| Investigation of phytoplankton from East China Sea of the Pacific Ocean, offshore Réunion Island of the Indian Ocean, and the French Atlantic coast revealed a species of poorly known armored fusiform dinoflagellate. To clarify this species, morphology and phylogeny based on mitochondrial and nuclear protein gene sequence (Cox1, Cob and Hsp90) concatenated with the SSU, ITS region and LSU rDNA sequences were analysed. Epifluorescence and scanning electron microscopy observations revealed that the nucleus of the specimen was elongated, sausage-shaped and located equatorially on the left lateral side of the cell, and that the plate formula is Po, 3′, 1a, 6″, 6C, 8S, 5‴, 1p, 2′‴. These morphological features indicate that the species can be assigned to... |
| Tipo: Text |
Palavras-chave: Fusiform dinoflagellate; Centrodinium; Alexandrium; Morphology; Phylogeny. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00483/59496/62364.pdf |
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| Chomerat, Nicolas; Bilien, Gwenael. |
| A new benthic phototrophic dinoflagellate is described from sediments of a tropical marine cove at Martinique Island and its micromorphology is studied by means of light and electron microscopy. The cell contains small golden-brown chloroplasts and the oval nucleus is posterior. It is laterally compressed, almost circular in shape when viewed laterally. It consists of a small epitheca tilted toward the right lateral side and a larger hypotheca. In the left view, the cingulum is more anterior and the epitheca is reduced. The cingulum is displaced and left-handed. This organism is peculiar in having no apical pore and its thecal plate arrangement is 2 ' 1a 7 '' 5c 3s 5 ''' 1 ''''. The plates are smooth with small groups of pores scattered on their surface.... |
| Tipo: Text |
Palavras-chave: Caribbean; Benthic; Dinophyceae; SEM; Phylogeny; Morphology; Taxonomy; Martinique; RDNA. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00195/30622/29458.pdf |
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| 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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| Tibiriçá, Carlos Eduardo Junqueira De Azevedo; Sibat, Manoella; Fernandes, Luciano Felício; Bilien, Gwenael; Chomérat, Nicolas; Hess, Philipp; Mafra, Luiz L.. |
| Coolia is a genus of marine benthic dinoflagellates which is widely distributed in tropical and temperate zones. Toxicity has been reported in selected Coolia species, although the identity of causative compounds is still controversial. In this study, we investigated the taxonomical and toxicological aspects of Coolia species from Brazil. Since light- and electron microscopy-based morphology was not enough to distinguish small-celled species, ITS and LSU D1-D3 phylogenetic analyses were used for species definition. Cultures of Coolia palmyrensis and Coolia santacroce were established from samples collected along the northeastern Brazilian coast, the first record of both species in South Atlantic waters. Cultures of Coolia malayensis and Coolia tropicalis... |
| Tipo: Text |
Palavras-chave: Benthic microalgae; Toxic dinoflagellates; Toxicity assay; Cooliatoxin; 44-methyl gambierone. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00630/74186/73789.pdf |
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| Caruana, Amandine; Ayache, Nour; Raimbault, Virginie; Rétho, Michael; Hervé, Fabienne; Bilien, Gwenael; Amzil, Zouher; Chomérat, Nicolas. |
| We confirm an amnesic shellfish poisoning risk associated with domoic acid production by the species Pseudo-nitzschia plurisecta and determine the toxin profile, which includes three domoic acid isomers. Although the species was reported once in European waters, along the Spanish Atlantic coast, here we describe and characterize P. plurisecta collected during the first occurrence in French Atlantic waters. Three strains (IFR-PPL-15.1, 15.2 and 15.3) were isolated from French coastal water samples in June 2015. These strains were identified and characterized by microscopic observation, molecular (ITS region sequencing and phylogenetic analysis) and metabolite (toxins and pigments) analyses. The cell shape is lanceolate and the valve contains a central... |
| Tipo: Text |
Palavras-chave: Coastal monitoring; Domoic acid; Pigment composition; Pseudo-nitzschia plurisecta; Taxonomic identification; Toxic diatoms. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00505/61687/66033.pdf |
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| Garvette, Andrea; Nezan, Elisabeth; Badis, Yacine; Bilien, Gwenael; Arce, Paola; Bresnan, Eileen; Gachon, Claire M. M.; Siano, Raffaele. |
| Parasites are key drivers of phytoplankton bloom dynamics and related aquatic ecosystem processes. Yet, the dearth of morphological and molecular information hinders the assessment of their diversity and ecological role. Using single-cell techniques, we characterise morphologically and molecularly, intracellular parasitoids infecting four potentially toxin-producing Pseudo-nitzschia and one Melosira species on the North Atlantic coast. These sequences define two, morphologically indistinguishable clades within the phylum Oomycota, related to the genera of algal parasites Anisolpidium and Olpidiopsis and the diatom parasitoid species Miracula helgolandica. Our morphological data are insufficient to attribute either clade to the still unsequenced genus... |
| Tipo: Text |
Palavras-chave: Pseudo-nitzschia; Diatoms; Marine oomycetes; Plankton parasites; Single-cell analysis; Metabarcoding. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00470/58135/60593.pdf |
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| Chomerat, Nicolas; Saburova, Maria; Bilien, Gwenael; Al-yamani, Faiza. |
| A new benthic dinoflagellate species, Prorocentrum bimaculatum sp. nov., is studied from Kuwaits marine sediments, based on detailed morphological and molecular data. Cells are large, oblong oval in shape. They are 49.955.3 mu m long and 38.443.2 mu m wide. The ornamentation of this new species is peculiar, and characterized by smooth valves with large pores (0.320.50 mu m) scattered on their surface, except in two circular patches of similar to 15 mu m in diameter, devoid of ornamentation and located on both sides of the valve centers. The periflagellar area is widely triangular, located in a moderate excavation of the right valve, and comprises nine platelets. The intercalary band of P. bimaculatum is smooth. The molecular phylogenetic position of this... |
| Tipo: Text |
Palavras-chave: Arabian Gulf; Benthic dinoflagellates; Kuwait; Molecular phylogeny; Morphology; Nuclear DNA; Prorocentrum; RDNA; SEM; Taxonomy. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00066/17756/15698.pdf |
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| Séchet, Veronique; Sibat, Manoella; Bilien, Gwenael; Carpentier, Liliane; Rovillon, Georges-augustin; Raimbault, Virginie; Malo, Florent; Gaillard, Sylvain; Perrière-rumebe, Myriam; Hess, Philipp; Chomérat, Nicolas. |
| Dinoflagellates of the genus Dinophysis are the most prominent producers of Diarrhetic Shellfish Poisoning (DSP) toxins which have an impact on public health and on marine aquaculture worldwide. In particular, Dinophysis acuminata has been reported as the major DSP agent in Western Europe. Still, its contribution to DSP events in the regions of the English Channel and the Atlantic coast of France, and the role of the others species of the Dinophysis community in these areas are not as clear. In addition, species identification within the D. acuminata complex has proven difficult due to their highly similar morphological features. In the present study, 30 clonal strains of the dominant Dinophysis species have been isolated from French coasts including the... |
| Tipo: Text |
Palavras-chave: Dinophysis spp; . Phylogeny; Taxonomy; Toxin profiles. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00679/79081/81880.pdf |
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| 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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| Registros recuperados: 21 | |
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