Hydra is hermaphrodite in which the male & female gonads occur in the same individual. In Hydra gonads develop temporarily from interstitial cells of epidermis for sexual reproduction, which accumulate to form bulges in the body wall. A single ovary develops towards the basal end of body & many testes develops towards the distal end. Hermaphrodite forms are protandrous in which testes mature earlier than ovaries.
[In brown Hydra as many as eight ovaries are formed].