Oysters are sea creatures that consist of salt water clams. These oysters are often eaten and considered a delicacy. Similar to the snail, the oyster can fertilize eggs as well as produce sperm cells. Oysters are then able to fertilize eggs on their own because they have their own gonads. Oysters reproduce when they sense other sperm cells in the water and then they release their gonads for the eggs to be fertilized. Once the egg is fertilized the reproduction system has ended.