378 



J.E. Hobbieetal. 



from the terrestrial moss community. Although tests of Arcella and 

 Diflugia were sometimes seen, they were rare and were not counted as it 

 requires observation of each individual to tell if the tests are occupied. 

 Small "limax-type" amoebae were occasionally observed with the 

 fluorescence microscope but could not be counted. 



Nematodes were the most abundant metazoan (Figure 8-14); their 

 numbers peaked at the beginning of July ( 10 ^ m ~ ') but most of these were 

 juveniles. By August, the number had declined to 1 to 3x10^ m \ This 

 pattern suggests that nematodes have only one generation per year in these 

 ponds. A similar pattern was noted for the harpacticoid copepods (Figure 

 8-15). During June and July nauplii were frequently found in the samples 

 but the first adults did not appear until the beginning of August. Rotifers 

 occurred throughout the summer at 3 to 8x10'* m"'. Philodina was the 

 most abundant of the six genera seen. Other metazoans found included 

 chaetonotid gastrotrichs, turbellarians, tardigrades, and ostracods. 



Carbon Flow 



From the biomass and feeding rates, it is possible to calculate the 

 carbon flow through the protozoans of the sediment (Figure 8-16). This 

 figure is based on the quantitative sample taken on 10 July 1973 and 



100 



o. o 



Q. ^ 



2| 



^ o 



80 



60 



40 - 



20 - 



nauplii . 



20 



Jun 



JU- 



20 



Jul 



10 



Aug 



FIGURE 8-15. Numbers of the nauplii and copepodites and 

 adults of harpacticoid copepods in the center of Pond A-B, 

 1973. 



