...the adult oyster at any time during its development is equipped with both the male and female reproductive organs, it spends its first year as a male and after the first spawning season where it releases sperm, it conserves energy for 2-3 years and then changes into female then starts releasing eggs instead, the time spent conserving energy is used in developing its female organs as it is said that more energy is expended in releasing eggs than that spent releasing sperm, the oyster can also change back into a male after spending time as a female, such changes is said to occur as a result of stress.

This is definitely one of the awesome and surprising work of God.