Table 9. Female to male sex ratios of winter flounder taken during the spawning 



period in the Niantic River from 1977 through 1986. 



1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 Mean C.V. 



AH fish captured 1.03 2.23 1.37 2.66 1.42 1.16 1.52 1.07 1.37 0.92 1.48 38% 



Measured fish 1.26 1.95 1.21 2.03 1.61 1.50 1.52 1.07 1.37 0.92 1.44 25% 



>20 cm 



analysis showed that the length of 50% sexual maturation of Niantic River females during 1981-86 was 

 26.8 cm with a 95% confidence interval of 26.3 to 27.3 cm. On an annual basis, values ranged from 25.1 

 cm in 1983 to 29.4 cm in 1981. Most of these fish were age 3 or 4. Males can mature at even smaller 

 sizes (down to 10-12 cm) and earlier ages (2) than females. 



Spawning 



Winter flounder spawning was followed by noting the weekly change in the percentage of gravid 

 females larger than 25 cm in the Niantic River. Generally, most spawning was completed by early April 

 (Fig. 5). Ice in the river prevented starting population surveys earlier in January or February, so for most 

 years approximately two-thirds of the females examined during late February had spawned before sampling 

 began. In most cases, spawning appeared to be correlated with water temperature. In relatively cold years 

 (1977-78, 1982), fewer females spawned during the earlier portion of the survey, whereas in warmer years 

 (1981, 1983-86) more were spent. No conclusions can be made about 1979 or 1980 (both cooler than 

 average) because of the late starts to these surveys and because relatively fewer females were examined in 

 comparison to other years. 



Fecundity and egg production 



The length-fecundity relationship for winter flounder taken in the vicinity of MNPS was determined 

 in two independent studies during 1977. In one, all fish were collected in the Niantic River and in the 



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