199

m. The difference between standing stock in the marsh

shortly after the marsh was flooded, July 9, and that when

the water level began to fall, around October 22, provides

another estimate of Mosquitofish production in the marsh

during the wet season, 0.42 g/sq-m. Values calculated by

the two methods show excellent agreement. Based on these

values and a growing time of 105 days (3.45 mos), the

production rate, or "r" in the growth equation (equation

19) in the Methods section, was 1.73.

 Table 17 shows respiration rates per milligram dry

weight fish for different size classes of Mosquitofish.

Table 18 shows the seasonal variation in calculated group

respiration over the period of study. A high negative

correlation (R = -0.84) was found between calculated group

Mosquitofish respiration rates for each sampling date and

Mosquitofish density (g/sq-m) on the same date. The

equation relating group respiration to biomass was:


 r = 2.846 1.037 B (26)



This equation, however, did not give a good fit to the data

at highest densities. A better approximation was provided

by the equation:


r = 2.6644 0.4454 B + 0.03143 B2


(27)