Transferts énergétiques entre l'huître Crassostrea gigas de 1 an et la nourriture potentielle disponible dans l'eau d'un bassin ostréicole

A paraIleI study of the available energy in the water and of the energy balance of one year old Crassostrea gigas has been made in Marennes-Oleron. Also, from the 32.95 \06 Kcal/m2 that goes through a waterspout of 0,1 m (5.96 \06 Kcal/m2 from phytoplancton, and 64.1 102 Kcal/m2 for the bacteria), an average of 0.19 70 is used by the oyster population. 5 343 Kcal of that annual consummate energy (20 383 Kcal) are assimilated, and 15 035 Kcal (73.8 70) are rejected as feces pseudofeces. From the assimilated energy, 4 317 Kcal (80.8 %) was available for the metabolism and 19.2 % for production of tissue (567 Kcal), shell (281 Kcal) and gametes (182 Kcal). However in the winter the production efficiency are negative ant it is considered that the overload in mineraI seston (≠ 250 mg.l-1) of the water is the main reason. A comparison with the energetic flow in adult Crassostrea gigas is discussed.