180 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



HOUR 



4 8 12 16 20 4 8 12 16 20 4 8 12 16 20 4 8 12 16 20 4 8 12 16 20 4 8 12 16 20 



- i    I I I I I i I i I I i I I r I I I I 



'Ill' 



16 20 4 



HOUR 



i i 'i i i 



12 16 20 



16 20 



Figure 12. — Example of extremes in pumping-rate response of two oysters to a common carbohydrate concentration 

 over an 18-day period plotted on a semilog scale. It is likely that oyster 88 had a glycogen reserve at the start, 

 so was not as dependent on external nutrients as was 87. 



