Zooplankton 291 



liter"'. Marshall (1973) reported that Calanus produced eggs at a food 

 concentration from 270 to 300 ^g C liter '. In D. rosea. Burns and Rigler 

 (1967) found that saturation began at about 190 Mg yeast C liter ' 

 Finally, McMahon and Rigler (1965) found that saturation began at 135 

 to 660 Mg C liter ' when yeast, Chlorella, or Escherichia coli were used. 



Production and Seston 



There was an inverse relationship between the mean concentration of 

 seston and the sum of the maximum biomass attained by each species of 

 zooplankton (Figure 6-17). The correlation coefficient of 0.946 (n = 8) is 



14 



12 



I I 



10 J2 



9 I 

 o 

 m 



0) 



200 400 600 800 1000 1200 



Maximal Zooplankton Biomass, /xqC liter'' 



FIGURE 6-17. Sestonic POC and percent algae and 

 bacteria of POC as a function of zooplankton den- 

 sity, 1971 to 1973. The value for Pond X in 1971 

 was omitted from the regression calculation as it 

 was heavily fertilized with phosphorus. 



