How Do Oysters Reproduce?

Have you guys wonder how do oysters make love in order to continue their species in this world and not going extinct?

I, myself have been wondering about this for quite some time and I decided to make a research about this topic after I went for a trip to Pangkor Island. Fyi, I'm only discussing about how oysters reproduce because clams, mussels and other shellfishes reproduce in a different way.

I've found out that, oysters reproduce in different ways than the regular birth process. Oysters use external fertilization. It means that the female oyster releases eggs where the male oyster releases sperm and they fuse in water.

Pheromones, a chemical substance secreted externally by some animals that influences the physiology or behavior of other animals of the same species is released by the first oyster that begins the process in to the water as a signal to the other oysters in the area that it's the right time to reproduce. Reproduction in oysters usually happens in the summer where the ocean temperature reaches approximately 23.9°C or 75°F . They are extremely fertile as the female oysters can release up to 5 million eggs while the male oysters can release up to 2.7 billion sperms! However, only 1 million larva can make it through their first week of life and some does not survive due to water conditions and predators.

Male and female oyster releasing sperms and eggs into water. Photograph by Robert Sisson, National Geographic.

After four hours, the sperm and egg fused, the larva began to has its organs and developed tissue. Up till two weeks, they floats around the water and begins to look for a permanent home. When the oysters drops to the ocean floor, they uses its foots to look for clutch or hard surface to stay permanent. They secretes cement from their byssus gland and stay there permanently. Oysters can start reproducing in its first year of life.

Life span of an oyster. Taken from www.vattenkikaren.gu.se. Translated by myself from Swedish into English.

SHOCKING FACT ABOUT THE GENDER OF AN OYSTER!

All oysters starts off life as a MALE and because they are hermaphroditic, ( (biology) of animal or plant; having both male female reproductive organs) they can change to females after one year. Within 3 years, 90% of the oysters are female. We can tell the gender of the oysters according to their size; small ones are males while large ones are females.

OYSTERS CANNOT BE A MALE AND FEMALE AT THE SAME TIME!

Article/research taken from www.ehow.com