During the reproductive season, spermatozoa and ovum are formed from interstitial cells in the hydra body stem. The testes are above and the ovaries are below. The testicles produce sperm and the ovaries produce eggs. Sperm are very small and nucleated. It consists of head, midsection and movable tail. Eggs are large, round and have three polar bodies.
Function of reproductive cells: Sperm and egg participate in reproductive function.