Abstract: | The effects of daily melatonin injections on female gonads in Rana ridibunda were examined. Melatonin-treated R. ridibunda maintained on a long photoperiod (18L:6D) had significantly smaller gonads than control animals. Thus, frogs injected daily with melatonin exhibited a substantial decrease in ovary weight when compared to saline-injected animals. Our findings suggest that melatonin exerts antigonadal effects in female Rana ridibunda. |