Maurice Héral

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Based on the individual growth, food limitation,population renewal through seeding, and individualmarketable size, a theoretical model of the culturedspecies population dynamics was used to assess thecarrying capacity of an ecosystem. It gave adome-shape curve relating the annual production andthe standing stock under the assumption of individual growth(More)
Ž . A model of bioenergetics of the black pearl oyster Pinctada margaritifera was built to simulate growth, reproduction and spawning in suspended culture at field sites in Takapoto lagoon Ž . French Polynesia . This model was based on allometric scaling of physiological functions and Ž . Ž y1. scope for growth SFG calculations. The input functions were(More)
Within the framework of an investigation into the carrying capacity of the Bay of Marennes-Oléron (France) for bivalve culture, thein situ uptake of suspended particulate material by oysters (Crassostrea gigas) and mussels (Mytilus edulis) was determined in experiments with benthic ecosystem tunnels. Very high fluctuations in seston quantity and quality(More)
An increasing number of hypotheses are being proposed to explain the faster growth potential of triploids in molluscs, including their partial sterility or their higher heterozygosity compared to diploids. Triploid advantage however, remains controversial for poorer sites, because of a potential trade-off with survival. These questions were addressed in(More)
Triploid oysters were induced using cytochalasin B upon retention of either the first (meiosis I triploids) or the second (meiosis II triploids) polar body in embryos from a single cohort derived from mixed parentage. Allozyme and microsatellite assays enabled the confirmation of both parentage and triploidy status in each oyster. Comparison of meiosis I(More)
Organotin salts, used as antilouling substances have a deleterious effect on the environment. particularly on molluscs and especially on the Japanese oyster Crassostrea gigas. A synthesis 01 the effects 01 tributyltin (TBT) on cultured molluscs reveals the lollowing effects: 1) acute and chronic loxicity to the adults; 2) accumulation in the f1esh 01 the(More)
Some of the particulate matter found in bottom sediment comes from material rejected as pseudofaeces or produces as faeces by Crassostrea gigas. The amount of pseudofaeces rejected is proportional to the amount of seston for total seston values up to 4.6 mg 1−1. For this values up to pseudofaeces production, the amount of faeces is mainly limitated by(More)
Oyster-pond sea-waters with natural populations were experimentally enriched to determine the nutrient limiting algal growth and the resulting effect on species composition. Results show that nitrogen is the limiting factor of growth-potential. N-NO3 alone is exhausted, while other ion concentrations remain always measurable. Addition of N-NO3 is needed to(More)
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