The quantitative estimation of reproductive cycle of a female catfish, mystus cavasius in relation to seasonal variation in photoperiod and water temperature of chambal river

The quantitative study of reproductive cycle of Mystus cavasius has been done in respect of gonadosomatic index and fecundity of fish. The gonadosomatic index of Mystus cavasius from Chambal River was observed from September, 2011 to August 2012 and fecundity was studied from May to August, 2012. The gonadosomatic index increased with the progressively development of gonad of the fish. The gonadosomatic index of this fish was increased significantly in May (6.06 ±0.09) and it reached its peak point in month of June (7.97±0.14) and lowest value of the gonadosomatic index of this fish was observed in the month of January (3.04±0.08). Therefore, the gonadosomatic index is in perfect positive correlation with the gonad weight. The correlation coefficient between gonadosomatic index and gonad weight were r = 0.9936. The fecundity of female species was varied from 6442.68±1293.38 to 18,707.95±1355.59 depending on gonad weight, body weight and age of fish. The maximum fecundity was observed in month of July and lowest was observed in the month of August. It has also shown a strong correlation with the gonad weight. The coefficient of correlation between fecundity and body weight was r = 0.888, fecundity and gonad weight was r = 0.993 and fecundity and body length was r = 0.496. The water temperature and photoperiod has also shown a close correlation with the gonadosomatic index and fecundity of the fish. The correlation coefficient between gonadosomatic index and water temperature and photoperiod were r = r = 0.654 and r = 0.872 respectively and regression equation between gonadosomatic index and water temperature and photoperiod were Y=0.1822x-0.2174 and Y= 1.0194x+7.451 respectively. The correlation coefficient between fecundity and water temperature and photoperiod were r = 0.1311 and r = 0.9399 respectively and regression equation between fecundity and water temperature and photoperiod were Y= -1733.8X+72494 and Y= 18338X – 236447 respectively.