7e-estradiol Has No Effect on Reproduction Success of Calanoid Copepod, Acartia Omorii

The natural estrogen 17 -estradiol (E2) is responsible for the endocrine disruption and also has potential effect on the reproduction of vertebrate. However, its effect on invertebrate reproduction has scarcely been studied. The present study was conducted to determine the effect of E2 on survival, egg production and egg hatch of calanoid copepod, Acartia omorii under bath administration. Survival was observed every 24h for 10 days. Each 10 individuals of adult female were incubated at different concentration of E2 (0.001, 0.01, 0.1, 1, 10 and 100 g/L) with food (Isochrysis sp.+Tetraselmis sp., ratio 1:1). Egg production was observed through the incubation of single gravid female with above same conditions. Egg hatching success was examined for each 100 eggs at different concentration of E2, which were obtained from preexposed female at the same concentration. More than 80% of survival was obtained in 100 g/L level after 96h exposure periods. Egg production was slightly increased in 100 g/L but not significant. No significant (P<0.05) effect of E2 was observed in hatching rate up to 100 g/L level. Result suggests that there is no effect of E2 on the reproduction success of the calanoid copepod, A. omorii in the coastal and marine environment.