Ovatoxin-a and Palytoxin Accumulation in Seafood in Relation to Ostreopsis cf. ovata Blooms on the French Mediterranean Coast

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) in both filter-feeding bivalve molluscs (mussels) and herbivorous echinoderms (sea urchins). The total content accumulated in urchins reached 450 µg PLTX eq/kg total flesh (summer 2008). In mussels, the maximum was 230 µg eq PLTX/kg (summer 2009) compared with a maximum of 360 µg found in sea urchins during the same period at the same site. This publication brings together scientific knowledge obtained about the summer development of Ostreopsis spp. in France during 2007, 2008 and 2009

Vulcanodinium rugosum gen. et sp. nov. (Dinophyceae), un nouveau dinoflagellé marin de la côte méditerranéenne française

Vulcanodinium rugosum gen. nov., sp. nov. (Dinophyceae): a new marine dinoflagellate from the French Mediterranean coast. A new armoured marine dinoflagellate, Vulcanodinium. rugosum Nezan et Chomerat, gen. nov., sp. nov. is described from water samples of Mediterranean lagoons. The thecal plate formula is Po, X, 4', 3a, 7 '', 6c, 6s, 5'", 2'. The apical pore plate Po is very large and a mucous matrix is extruded from its centre. The plate X is rather long and just below is the narrow and short first apical plate 1'. The intercalary anterior plates are contiguous. The first cingular c1 plate is narrow. The number, the shape of plates and the presence of lists characterize the sulcus. The thecal surface is covered by longitudinal striae with often cross reticulations and is perfored by large pores. According to the studied feature, the morphology of Vulcanodinium rugosum looks like, either a peridinioid or a gonyaulacoid species. A phylogenetic study, based on LSU rDNA sequence data, confirms that this taxon is new and that it belongs to the order Peridiniales. However, it is not possible to affiliate it neither to a particular family nor to a known genus. As a consequence, a new generic name, Vulcanodinium is proposed with V. rugosum as type species, assigned in the order Peridiniales, incertae sedis for the time being

Guide pratique à l'usage des analystes du Réseau National de Surveillance du phytoplancton

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 classesCe guide a été conçu comme outil de travail destiné en premier lieu aux analystes du Réseau National de Surveillance (REPHY). Pour élaborer ces fiches, nous avons tenu compte des moyens d'observation dont ils disposent. C'est la raison pour laquelle nous avons sélectionné une grande majorité de photographies réalisées en microscopie optique. Ce document vise à apporter une aide à l'identification des organismes phytoplanctoniques rencontrés sur les côtes françaises et à concourir à la normalisation des résultats d'examens microscopiques. Il se présente en trois parties : 1) les dinophycées que l'on appelle communément les dinoflagellés ou périnidiens. Dinophyceae- dinoflagellate 2) les bacillariophycées ou diatomophycées que l'on appelle communément les diatomées. 3) les autres classes. Vu l'intérêt qu'il peut susciter, nous avons traité en annexe le cilié photosynthétique Mesodinium rubrum

Toxic and Harmful Microalgae of the World Ocean. IOC Manuals and Guides, 68

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.Cet ouvrage met a Jour et complete les donnees internationales disponibles sur les especes toxiques et nuisibles du phytoplancton et du micro-phytobenthos. II fait l'inventaire des occurrences regionales a l'echelle de la planete : localites, densites cellulaires, niveau de toxicite des animaux contamines, intoxications humaines et animales, isolement des principes actifs et/ou des toxines identifiees, sources documentaires. Enfin, cet ouvrage aborde la distribution geographique des producteurs de phycotoxines a partir de donnees recentes. L'objectif est d'analyser !'evolution des episodes toxiques et nuisibles sur les 30 dernieres annees afin de degager des tendances et d'introduire une discussion sur la realite d'une augmentation du nombre d'especes et de toxines connues au cours du temps

Description and phylogenetic position of Plagiolemma distortum sp. nov., a new raphid diatom (Bacillariophyceae) from French coastal waters

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 raised on a ridge and ending in external large openings with elaborate internal helictoglossae. Moreover, each valve displays outer slit-like foramina and inner rounded hymenes, external terminal minute holes (micropyles) arranged in a row at the poles. In addition, on each valve face, one to several short transverse median costae are observed, terminating far away from the valve edges. Morphological comparisons with closely related taxa show that P. distortum is a new species. A video clip of a moving cell is provided for better understanding of the cell shape. The formation and function of capsules are discussed as well as the species habitat. A phylogenetic study, based on nuclear small subunit (SSU) ribosomal DNA (rDNA) sequence data, which includes new sequences relative to Plagiolemma and Plagiotropis, was performed. Furthermore, some morphological details observed with SEM are included in an emended generic diagnosis of Plagiolemma

Morphological and Molecular Characterisation of Three New Azadinium Species (Amphidomataceae, Dinophyceae) from the Irminger Sea

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 elongated 1′ plate. Azadinium concinnum sp. nov. was of particular small size (< 10 μm) and characterized by an anteriorly elongated anterior sulcal plate and by large and symmetric precingular plates. The ventral pore was located inside the apical pore plate on the cells’ right lateral side. Molecular phylogenetics as inferred from concatenated SSU rDNA, ITS, and LSU rDNA sequence data supported the distinctiveness of the three new species. None of the new species produced any known AZAs in measurable amounts

Micro-algues des claires ostréicoles de Charente Maritime : focus sur les producteurs potentiels de toxines DSP, PSP et ASP et toxines émergentes (palytoxines, pinnatoxine...)

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 toxique. Leur présence est recherchée dans l'eau, dans le sédiment et à l'interface eau-sédiment

DYNAPSE - DYNamiques des efflorescences et de la toxicité des espèces phytoplanctoniques nuisibles du genre PSEudo nitzschia en région Loire Bretagne

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 mais également leur toxicité. A cette complexité s’ajoute un temps de décontamination très long des coquilles Saint Jacques qui met en péril les flottilles de pêche côtière et a, pour certaines zones, entraîné une création d’une filière de décorticage. Il est urgent aujourd’hui, aussi bien pour les scientifiques que pour les gestionnaires et professionnels et du milieu marin, d’arriver à comprendre comment se produisent les toxicités liées à Pseudo-nitzschia, quelles sont les espèces qui en sont responsables et quels facteurs les favorisent

Inter and intra-specific growth and domoic acid production in relation to nutrient ratios and concentrations in Pseudo-nitzschia : phosphate an important factor

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 a higher phosphate concentration resulted in low cell densities, but without high DA production. Inter-species effects were also observed in DA production, where P. australis represented the most toxigenic species of all. Intra-specific variations were only moderate, except for a recently isolated P. australis strain, suggesting the influence of time since isolation on the physiology and DA production of Pseudo-nitzschia species. Overall, the lack of strong interaction between environmental and genotypic factors showed that the various genotypes investigated did not extensively diverge in their ability to respond (in terms of DA production and cell densities) to contrasting nutrient supply