Effect of cobalt-60 gamma radiation on reproductive disturbance in freshwater prawn Macrobrachium rosenbergii (De Man, 1879)

Abstract

The present study was designed to evaluate the effect of acute level of 60Co gamma radiation on fecundity of freshwater prawn Macrobrachium rosenbergii. Prawns were exposed to four different dose levels (3, 30, 300 and 3000 mGy) and their reproductive disturbances i.e Gonadosomatic Index (GSI), Egg Clutch somatic Index (ESI), Egg Counts and Egg hatching rates were calculated. The experimental group showed significant reduction in GSI (0.47 ± 0.01) & ESI (1.22 ± 0.08) after exposure to 60Co gamma radiation. Egg Count (3713 ± 21) and Egg hatching rates (3798 ± 11) were significantly reduced in all irradiated groups. The number of dead larva increased with the increasing level of doses. With the increase in dosage level, the gonad and egg clutch weight were decreased which likely lead to reduced number of eggs. Our results proved that even low level of ionizing radiation (60Co) affects the fecundities of freshwater crustacean M. rosenbergii. Keywords: M. rosenbergii, GSI, ESI, 60Co, Egg count, Egg hatching