Because of its ability to form reefs and to filter large amounts of water, the Eastern Oyster, Crassostrea virginica (Gmelin, 1791) is an important organism living in the bays of Southwest Florida. Young oysters, called spats, live drifting in the water until it is time to settle to bottom. At that time, spats prefer to settle on and cement themselves to existing oyster shells: this is one of the reasons why oysters form large reefs that serve as homes for a myriad other marine organisms.
The photo shows an Eastern Oyster shell from the bay side of Sanibel. Photos by José H. Leal.