Study on Gonadosomatic index (GSI) during the three seasons (pre-spawning, spawning and post-spawning periods) of Schizothorax niger Heckel in dal lake, Kashmir

Abstract

The present study was conducted to investigate changes in Gonadosomatic index (GSI) of Schizothorax niger Heckel during the three seasons (pre-spawning, spawning and post-spawning periods) in Dal Lake, Kashmir from November, 2014 to July, 2015. Fishes ranging in length from 75-374mm and in weight from 56-557g were taken during the study. The mean GSI of the fish Schizothorax niger Heckel was found to be 7.94 and its range varied from 0.78-27.28. The mean value of GSI in S. niger Heckel during pre-spawning period was found as 2.02±1.22. During spawning and post-spawning periods, the mean values of GSI were recorded as 20.37±3.87 and 1.43±0.42 respectively. The results suggest that the maximum Gonadosomatic Index in Schizothorax niger Heckel were recorded in March, i.e. during spawning period (mean value of 20.37 in females). The GSI then started decreasing gradually and was recorded minimum in July (mean value of 1.43 in females). Thus the peak breeding season of the fish during the present study was found in March. Absolute Fecundity and Relative Fecundity of S. niger were recorded with a mean values of 21981.60 and 109.82 respectively. A positive correlation was observed during spawning period between GSI and Relative Fecundity at p<0.05 level of significance. Understanding reproductive behaviour of fishes is not only important for elucidating the basic biology of the fishes but it can also help in their management and conservation.