Oysters usually reach maturity in one year. They are protandric; during their first year, they spawn as males by releasing sperm into the water. ... The eggs become fertilized in the water and develop into larvae, which eventually find suitable sites, such as another oyster's shell, on which to settle.

Do oysters grow their own shells?

Pacific oysters, for example, begin building their shells 14–18 hours after the egg is fertilized, laying down a shell made of aragonite. The larva continues life in the form of plankton for the next two to three weeks, feeding on microalgae, until it grows a foot to stick down to a hard surface.

How are oysters born?

During an oysters spawning season, the young male releases his sperm and the older females release their eggs. Sometimes up to hundreds of million eggs. One the met they develop larvae. Larvae takes 6 hours to develop and a few weeks to settle into another oyster shell or rocky place.