Ismael Bernard

Eurêka Mer

Inter-individual transmission of cancer cells represents a unique form of microparasites increasingly reported in marine bivalves. In this study, we sought to understand the ecology of the propagation of Mytilus trossulus Bivalve Transmissible Neoplasia 2 (MtrBTN2), a transmissible cancer affecting four Mytilus mussel species worldwide. We investig...

Transmissible cancer, a unique form of microparasites that spreads through direct transmission of living cancer cells, is increasingly reported in marine bivalves. In this study, we sought to understand the ecology of the propagation of Mytilus trossulus Bivalve Transmissible Neoplasia 2 (MtrBTN2), a transmissible cancer affecting four Mytilus muss...

Transmissible cancers are parasitic malignant cell lineages that acquired the ability to infect new hosts from the same species, or sometimes related species. First described in dogs and Tasmanian devils, transmissible cancers were later discovered in some marine bivalves affected by a leukemia-like disease. In Mytilus mussels, two lineages of Biva...

Transmissible cancers are parasitic malignant cell lineages that acquired the ability to infect new hosts from the same species, or sometimes related species. First described in dogs and Tasmanian devils, transmissible cancers were later discovered in some marine bivalves affected by a leukemia-like disease. In Mytilus mussels, two lineages of Biva...

The aim of this study was to summarise the literature reporting the risk factors for mortality in the mussel species Mytilus edulis and Mytilus galloprovincialis in order to identify potential science‐based solutions to prevent or mitigate mussel mortality outbreaks. We followed the PRISMA methodology: Preferred Reporting Items for Systematic Revie...

This note describes the first detection of the bacteria Francisella halioticida in mussels Mytilus spp. from locations in Normandy and northern Brittany (France) experiencing high mussel mortalities, while it was not detected in Bay of St Brieuc (N Brittany), which was not affected by abnormal mussel mortality. The distribution of the bacteria in m...

In 2014, a high and unusual mass mortality of mussels occurred in several important production areas along the French coasts of the Atlantic and English Channel. In the first quarter of 2016, mass mortalities hit farms on the west coast of the country once again. These heterogeneous mortality events elicited a multi-parametric study conducted durin...

The recent discovery of Pacific oyster Crassostrea gigas (also known as Magallana gigas) spatfields in a Mediterranean lagoon intensely exploited for shellfish farming (Thau lagoon) revealed significant contrasts in spatial patterns of recruitment. We evaluated the processes that drive spatial patterns in oyster recruitment by comparing observed re...

Human‐mediated transport creates secondary contacts between genetically differentiated lineages, bringing new opportunities for gene exchange. When similar introductions occur in different places, they provide informally replicated experiments for studying hybridisation. We here examined 4279 Mytilus mussels, sampled in Europe and genotyped with 77...

Human-mediated transport creates secondary contacts between genetically differentiated lineages, bringing new opportunities for gene exchange. When similar introductions occur in different places, they provide informally replicated experiments for studying hybridisation. We here examined 4279 Mytilus mussels, sampled in Europe and genotyped with 77...

Marine mussel production is of substantial economic interest in numerous coastal areas worldwide, making crucial the study of pathologies that affect them. Disseminated neoplasia (DN) has recently been suggested to be linked to blue mussel, Mytilus edulis, mortality outbreaks observed in France since 2014, although the evidence remains indirect. In...

La recherche bibliographique maximalisée réalisée dans le cadre de cette revue systématique de la littérature a permis de décrire le paysage de la connaissance existante sur les facteurs de risque de mortalité des espèces de moules M. edulis et M. galloprovincialis. Ces travaux ont abouti à la formalisation d’une méthodologie rigoureuse, transparen...

Reproduction and recruitment of benthic invertebrates are influenced by the climate and by the ecological structure of marine ecosystems, along with local anthropogenic pressures such as eutrophication or oligotrophication. Using the Pacific oyster Crassostrea gigas as a biological model, we tested the hypothesis that the variability in prodissocon...

Il s'agit du troisième rapport technique sur les mortalités de moules en Bretagne Nord pour le CRC Bretagne Nord

Neoplasia is a pathological process that consists in an uncontrolled and irreversible proliferation of atypical cells. The presence of two predominant types of malignant neoplasia has been confirmed in various marine bivalve species: a germinoma and a "disseminated neoplasia", also called "haemic neoplasia", characterised by the proliferation of ab...

In the context of increasing demand for environmental recovery, aquatic systemsmay face the challenge of evolving under oligotrophication. This is the case in Mediterranean lagoons, in particular the shellfish-farmed Thau lagoon in France, where we studied recruitment of the Pacific oyster Crassostrea gigas. Oyster spat and environmental parameters...

Il s'agit du second rapport technique sur les mortalités de moules pour le CRC Bretagne Nord.

The Thau lagoon, located at the South of France, provides 10% of the French pacific oyster Crassostrea gigas production. Despite this intensive shellfish production, the larval recruitment of this species within the Thau lagoon is still misunderstood and spat collection remains highly variable; as a consequence, shellfish farmers rely mostly on hatche...

In macrotidal coastal ecosystems, spatial heterogeneity of the water column properties is induced by both oceanic and continental influences. Hydrodynamic processes generate a land-sea gradient of environmental conditions, affecting the biological performances of sedentary organisms. The aim of the present study is to establish an extensive spatial...

In macrotidal coastal ecosystems, spatial heterogeneity of the water column properties is induced by both oceanic and continental influences. Hydrodynamic processes generate a land-sea gradient of environmental conditions, affecting the biological performances of sedentary organisms. The aim of the present study is to establish an extensive spatial...

Il s'agit du premier rapport technique sur les mortalités de moules pour le CRC Bretagne-Nord.

The precise environmental conditions under which broadcast spawners spawn in the field remain largely unknown. We investigated this issue in the oyster Crassostrea gigas using three different methods at different time scales in two traditional oyster farming areas of the French Atlantic Coast, the Bay of Arcachon and Marennes-Oléron. We directly re...

Pacific oyster hatchery production remains highly variable, partially due to inconsistent gamete quality. However, little attention has been paid to oocyte quality in Pacific oyster compared to important vertebrate aquaculture species such as fishes. The aims of the present study were to identify criteria of oocyte and trochophore quality used as p...

Fort appréciée du temps des Romains et très consommée jusqu’au XXème siècle, l’huître plate (Ostrea edulis), huître indigène de nos côtes européennes, ne tient plus aujourd’hui qu’une place anecdotique dans nos assiettes. En France, et plus précisément en Bretagne, des ostréiculteurs et des scientifiques se mobilisent afin d’envisager à nouveau une...

De 2009 à 2011, le captage à Arcachon fut particulièrement mauvais. Des pontes tardives associées à de faibles quantités de larves “petites” indiquaient un problème probablement au niveau de la maturation ou de la ponte. Le programme FéLiBA consiste en un zoom, pour l’année 2013, sur la Fécondité des huîtres creuses en Lien avec la qualité de l’eau...

La forte augmentation des mortalités de juvéniles d’huître creuse depuis 2008 a relancé la problématique de l’approvisionnement en naissains de l’ostréiculture française. Dans ce contexte, cette étude a pour objectif d’étudier la faisabilité d’opérations de repeuplement en huîtres génétiquement plus résistantes, afin d’améliorer les performances de...

This work assesses the present knowledge on Pacific oyster sperm biology in comparison to two marine fish species (tur-bot and seabass) whose sperm characteristics are well described. Sperm morphology mainly differs by the presence of an acrosome in Pacific oyster which is absent in both fish species. In turbot as in Pacific oyster, a sperm 'matura...

DEB theory can be used to obtain a detailed description of energy allocation in organisms and the control of this allocation by temperature and food concentration. In this study, we modified the model of Bourlès et al. (2009) developed for the Pacific oyster, Crassostrea gigas, to improve the description of reproductive effort. The model was amende...

Spat collecting supplies numerous oyster-farmers with young cupped oyster, C. gigas.Since the end of the nineties, professionals have noticed an increasing variability of the number of spat among years. This thesis aimed to identify the origin of the variability of oyster recruitment. This question is addressed by different methods for each step of...

Dynamic Energy Budget (DEB) theory aims to quantify the energetic framework of an individual organism as a dynamic model, from the uptake of food to its utilisation in metabolic processes (maintenance, growth, development and reproduction). The purpose of the present paper is to extend the existing DEB model for adult Pacific oyster Crassostrea gig...

In France, spatfall of Pacific Oysters occurs traditionally in two shellfish area of the south west of France: the Marennes-Oléron bay and the Arcachon basin. The spat collected in both sites ensures approx. 70 % of the need of the French oysters production (the other part is produced in hatcheries). But, since ten years, recruitment have become hi...