191

average biomass of fish per square meter of surface water

area when the marsh was initially flooded in late June was

0.09 mg dry wt/sq-m.

 Figure 45 shows the seasonal change in the length-

frequency distribution of Mosquitofish in samples from July

9, 1974, through June 12, 1975. Smaller individuals

predominated from June through September 1974. A higher

percentage of larger individuals was found October 1974

through June 1975. Two periods of Mosquitofish recruitment

were observed during the wet season of 1974. The first

occurred at the beginning of sampling in early June and the

second was obvious by August.

 Percent females and percent gravid females on each

sampling date are shown in Figure 46. There were more

females than males in almost every collection. Ninety

percent of several collections were females. More males

were collected during July and August than in other months.

The high percentage of females encountered in this study is

consistent with the preponderance of females in

Mosquitofish populations in Louisiana reported by Barney

and Anson (1921).

 The maximum incidence of gravid females was during the

month of June in both 1974 and 1975. Gravid females were

present from July through October, 1974, but were absent

from November, 1974, through February, 1975. Gravid

females began reappearing in the samples in March. The

occurrence of gravid females in the samples preceded the