Consulta: creatorFacets:"Nezan, Elisabeth"
Registros recuperados: 31
Data/hora: 10/06/2024 03:34:05

Genetic diversity of the harmful family Kareniaceae (Gymnodiniales, Dinophyceae) in France, with the description of Karlodinium gentienii sp. nov.: A new potentially toxic dinoflagellate
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Morphology and molecular phylogeny of prorocentrum consutum sp. nov. (dinophyceae), a new benthic dinoflagellate from south Brittany (northwestern France)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

DYNAPSE - DYNamiques des efflorescences et de la toxicité des espèces phytoplanctoniques nuisibles du genre PSEudo nitzschia en région Loire Bretagne
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Description and phylogenetic position of     Plagiolemma distortum     sp. nov., a new raphid diatom (Bacillariophyceae) from French coastal waters
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Growth anomalies in Pecten maximus from coastal waters (Bay of Brest, France): relationship with diatom blooms
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Algal toxin profiles in Nigerian coastal waters (Gulf of Guinea) using passive sampling and liquid chromatography coupled to mass spectrometry
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Pseudo-nitzschia australis on French Atlantic coast - an unusual toxic bloom
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Nezan, Elisabeth; Chomerat, Nicolas; Bilien, Gwenael; Boulben, Sylviane; Duval, Audrey; Ryckaert, Mireille.
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00008/11949/8657.pdf

Morphological and Molecular Characterisation of Three New Azadinium Species (Amphidomataceae, Dinophyceae) from the Irminger Sea
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

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
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Satellite and in situ observations of a late winter phytoplankton bloom, in the northern Bay of Biscay
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Gohin, Francis; Lampert, Luis; Guillaud, Jean-francois; Herbland, Alain; Nezan, Elisabeth.
A phytoplankton bloom was observed in late winter 2000, on the continental shelf offshore of southern Brittany, in northwestern Bay of Biscay. This bloom appeared initially along the 120-m isobath, in stratified and clear waters, at the interface between the oceanic water and the plumes of southern Brittany rivers (mainly the Loire and Vilaine). The development of the bloom was triggered by favourable meteorological conditions, characterised by solar irradiance reaching the maximum level expected for that period of the year. Outside of the bloom area, the phytoplankton photosynthesis was irradiance limited: inshore, because of the stronger attenuation of the light; offshore, because of the weak stratification. The hydrological conditions at the onset of...
Tipo: Text
Palavras-chave: Bay of Biscay; Coscinodiscus; Algal bloom; Phytoplankton; Ocean colour; Satellite sensing.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-463.pdf

Pentaplacodinium saltonense gen. et sp. nov. (Dinophyceae) and its relationship to the cyst-defined genus Operculodinium and yessotoxin-producing Protoceratium reticulatum
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

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
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Inter and intra-specific growth and domoic acid production in relation to nutrient ratios and concentrations in Pseudo-nitzschia : phosphate an important factor
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Paralytic Shellfish Poisoning on French Mediterranean coast in the autumn of 1998:Alexandrium tamarense as a causative agent
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Masselin, Pierre; Amzil, Zouher; Carreras, Antoni; Chiantella, Claude; Le Bec, Claude; Nezan, Elisabeth; Truquet, Philippe.
Tipo: Text
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00017/12871/9821.pdf

The Bay of Brest (France), a new risky site for toxic Alexandrium minutum blooms and PSP shellfish contamination
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Chapelle, Annie; Le Gac, Mickael; Labry, Claire; Siano, Raffaele; Quere, Julien; Caradec, Florian; Le Bec, Claude; Nezan, Elisabeth; Doner, Anne; Gouriou, Jeremie.
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00278/38921/37461.pdf

First record of resting cysts of the benthic dinoflagellate     Prorocentrum leve     in a natural reservoir in Gujan-Mestras, Gironde, France
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Dynamics of phytoplankton communities in eutrophying tropical shrimp ponds affected by vibriosis
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

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?
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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 &amp;#956;g 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.
Tipo: Text
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-6331.pdf

Variability patterns of microphytoplankton communities along the French coasts
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Gailhard, Isabelle; Gros, Philippe; Durbec, Jp; Beliaeff, Benoit; Belin, Catherine; Nezan, Elisabeth; Lassus, Patrick.
Microalgal populations along French coasts (English Channel, Bay of Biscay and Mediterranean Sea) have been sampled twice a month since 1987 within the context of the French Phytoplankton and Phycotoxin Monitoring Network (REPHY). This study used these data to characterize the large-scale geographical structures of microphytoplankton communities and to determine whether 'homogeneous' geographical areas exist in which microalgal populations display similar temporal variability schemes. Once the temporal variability component shared by all sampled coastal sites was identified, the 'residual' site-specific component was analyzed. Multivariate ordination methods were used to determine seasonal and inter-annual variability. The expected-temporal pattern common...
Tipo: Text
Palavras-chave: Microphytoplankton; French coast; Geographical structure; Temporal variability; RV coefficient; Multidimensional scaling.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00000/10033/7596.pdf

Fragilidium duplocampanaeforme sp nov (Dinophyceae): A new phagotrophic dinoflagellate from the French Atlantic coast
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Ovatoxin-a and Palytoxin Accumulation in Seafood in Relation to Ostreopsis cf. ovata Blooms on the French Mediterranean Coast
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Amzil, Zouher; Sibat, Manoella; Chomerat, Nicolas; Grossel, Hubert; Marco-miralles, Francoise; Lemee, Rodolphe; Nezan, Elisabeth; Sechet, Veronique.
Dinoflagellates of the genus Ostreopsis are known to cause (often fatal) food poisoning in tropical coastal areas following the accumulation of palytoxin (PLTX) and/or its analogues (PLTX group) in crabs, sea urchins or fish. Ostreopsis spp. occurrence is presently increasing in the northern to north western Mediterranean Sea (Italy, Spain, Greece and France), probably in response to climate change. In France, Ostreopsis. cf. ovata has been associated with toxic events during summer 2006, at Morgiret, off the coast of Marseille, and a specific monitoring has been designed and implemented since 2007. Results from 2008 and 2009 showed that there is a real danger of human poisoning, as these demonstrated bioaccumulation of the PLTX group (PLTX and ovatoxin-a)...
Tipo: Text
Palavras-chave: Ostreopsis cf. ovata; Palytoxin; Ovatoxin-a; LC-MS/MS; Seafood.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00071/18230/15799.pdf

Novel Widespread Marine Oomycetes Parasitising Diatoms, Including the Toxic Genus Pseudo-nitzschia: Genetic, Morphological, and Ecological Characterisation
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Projet de Sciences Participatives. HERMIONA II, 1 - Protocoles
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Bec, Claude; Nezan, Elisabeth; Mertens, Kenneth; Terre Terrillon, Aouregan; Baudrier, Jerome; Even, Francoise.
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58279/60807.pdf

First record of the genus Azadinium (Dinophyceae) from the Shetland Islands, including the description of Azadinium polongum sp. nov.
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Mortalités de poissons d'élevage par phytoplancton toxique Camaret (Finistère), automne 1994
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Kempf, Marc; Merceron, Michel; Nezan, Elisabeth.
Brown water was observed in Camaret Cove, on 27 and 28 September 1994, because of the massive proliferation of a toxic phytoplankton alga. The densities reached by this alga were considerable: from 1.5 million cells per litre at a point far from the coast to 130 million cells per litre at the height of the efflorescence at the bottom of the bay, in the port's waters. The toxicity of this alga caused deaths in the farms of salmonids in cages set up at this site. The SEMII (IFREMERINRA research facility) experimental farm recorded 100% losses (15-20% on 27 September and the entire remaining stock during the night of 27-28 September), which is around 10 tonnes of fario trout and 0.5 tonne of Atlantic salmon. Aside from the economic loss, this represents a...
Tipo: Text
Ano: 1995
URL: http://archimer.ifremer.fr/doc/1995/publication-2831.pdf

Chaetoceros armatum - Diatomée de la zone de ressac, vecteur d'efflorescences colorées hivernales - Cas de la Baie d'Audierne, plage de Tronoën
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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.
Tipo: Text
Ano: 1995
URL: http://archimer.ifremer.fr/doc/00017/12806/9749.pdf

Cabra reticulata sp. nov. (Dinophyceae), a new sand-dwelling dinoflagellate from the Atlantic Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Guide pratique à l'usage des analystes du Réseau National de Surveillance du phytoplancton
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Micro-algues des claires ostréicoles de Charente Maritime : focus sur les producteurs potentiels de toxines DSP, PSP et ASP et toxines émergentes (palytoxines, pinnatoxine...)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Micro-algues toxiques et nuisibles de l’océan mondial. COI Manuels et Guides, 68
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00379/49054/49508.pdf

Morphology, ultrastructure and molecular phylogeny of cyst-producing Caladoa arcachonensis gen. et sp. nov. (Peridiniales, Dinophyceae) from France and Indonesia
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Luo, Zhaohe; Mertens, Kenneth; Nezan, Elisabeth; Gu, Li; Pospelova, Vera; Thoha, Hikmah; Gu, Haifeng.
The dinoflagellate order Peridiniales encompasses several well circumscribed families. However, the family level of some genera, such as Bysmatrum and Vulcanodinium, has remained elusive for many years. Four Peridinium-like strains were established from the Atlantic coast of France and North Sulawesi, Indonesia through cyst germination or isolation of single cells. The cyst-theca relationship was established on specimens from the French Atlantic. Their morphologies were examined using light, scanning and transmission electron microscopy. The cells were characterized by a much larger epitheca relative to the hypotheca, a large anterior sulcal (Sa) plate deeply intruding the epitheca and a small first anterior intercalary plate. The plate formula was...
Tipo: Text
Palavras-chave: Bysmatrum; Cyst; Dinoflagellate; Eyespot; Peridiniales; Plate overlap.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00489/60112/63564.pdf