The energetic values measured by the direct method and estimated by biochemical analysis of the annual cycle of ash-free dry weight of two Crassostrea gigas populations, show that the analytic results are inferior by 30% to those obtained by direct evaluation. The mean energetic amount is 4.84 cal.mg-1. Its seasonal variations, from 4.11 to 5.39 cal.mg-l, mainly depend on variations in the values of lipids. The mean conversion factor of lipids is 8.63 cal.mg-!, noticeably different from Brody's (9.45 caI.mg-I). This coefficient varies according to seasons from 7.85 to 9.38 cal.mg'-I. According to the biochemical evaluations, female oysters appear to he more energetic than male oysters when gonads are full. Direct evaluations, on the other hand, show no... |