216


 The estimated total dry weight of gar in the pond is

given in Table 23. The average dry weight of the gar

collected in the pond on each date is shown in Table 24.

The approximate number of gar in the pond was: 750 on

March 31, 256 on April 28, and 106 on June 12. A decline

in total number could be expected, since at least one

alligator resided in the pond. One anomaly was that the

gar collected on April 28 averaged 46% larger than those

collected on March 31 and 37% larger than those collected

on June 12. This size fluctuation may have been due to

differential predation by predators. The larger average

weight of the gar collected on April 28 also might have

been due to half the gar being heavy with eggs. Spawning

prior to June 12 would explain why the average weight of

gar collected on June 12 was lower than that on April 28.

 The energy-flow diagram and equations used to model

 food intake, growth, and consumption by an average-size gar

 were given in the preceding section. Assuming the gar were

 maintaining a low level of activity, double the resting

 metabolism, the total population required a minimum of 385

 kg dry wt of fish, or the caloric equivalent of other

 organisms, to survive the dry season and increase their

 weight by the measured 180, during the period from November

 26, 1974, to June 23, 1975. This energy demand more than

 accounts for the loss of Mosquitofish biomass from the pond

 area between January 22 and March 31 and the depredation of

 the population of small Bluegill between November 26 and