Seasonal variations in the gonadosomatic index of an Indian major carp, Labeo rohita (Ham).

The study was conducted to determine the changes in the gonadosomatic index (GSI) of an Indian major carp, Labeo rohita. The fish has only one spawning season of short duration, running from July to August as indicated by the peaks of GSI and the diameter of oocytes and testicular lobules. Both males and females mature simultaneously. The minimum GSI for female was 0.74±0.12 in resting phase and maximum was observed in the spawning phase (16.49±1.70). The GSI for males was minimum in resting phase (0.087±0.004) and maximum in spawning phase (2.02±0.181).