Influence de la densite et de l'age des huitres japonaises (Crassostrea gigas ) sur la croissance et la composition biochimique en bassins de terre

Two different biomasses (100 g multiplied by m super(-2) and 1 kg multiplied by m super(-2)) of oysters were put in identical sea-water ponds, thus leading to different trophic conditions, corresponding to rearing techniques. Changes in growth, biochemical composition and sexual maturation were recorded for two age groups. The first one included 9 month-old oysters and the second one 21 month-old oysters, at the beginning of the experiment. For both age groups, significant differences were observed in growth and biochemical composition. Lipids were accumulated faster for the lower biomass. However, the only difference concerning glycogen was observed on the older oysters. They showed a peak at the lowest biomass and a decrease at the larger biomass. Sexual maturation was observed in every condition. These results were discussed with regards to the biological cycle under rearing conditions.