Fig. 8. Concentrations of succinate in foot, adductor muscles and gills (µmol g^-1 fresh mass) and in the mantle cavity fluid (µmol ml^-1) of C. fluminea in controls and after different times within `voluntarily' closed valves. Clams were taken out of the Mosselmonitor® (MM), where they experienced a permanent flow of well-aerated artificial freshwater at 15°C without light. Values are means ± S.D.; numbers above the bars indicate the number of animals analysed. ^*Significant difference (P<0.05) compared to the controls; significant difference (P<0.05) of a whole group of tissues from the controls.