Oysters and Clams
The South Carolina oyster fishery is based entirely on the eastern oyster, Crassostrea virginica. Although other oysters are grown on the west coast, no other commercially important oyster species occurs on the east coast. The oyster is one of the most popular local seafoods. It is readily available and can be served in a variety of appetizing ways. Oysters are not only palatable, but also contain a number of vitamins, minerals, carbohydrates and proteins.
The oyster feeds by filtering food particles from the surrounding water. Opening and closing of the valves are controlled by an adductor muscle attached to each shell. Food and other particulate matter, suspended in the water, are drawn into the oyster by the motion of small, fringe-like whips called cilia located on the gills. The quantity of water pumped by a large, healthy oyster may approach four gallons per hour. Food particles retained by the gills are conducted by ciliary action to the mouth and then to the stomach of the oyster. Matter brought into the shell, but not passed through the mouth, is collected by mucus on the gills and then discharged. Large amounts of silt are rejected in this manner. This ability to separate food from silt apparently allows oysters to survive in waters of high turbidity which occurs in many estuaries. The filtering action of oysters can play an important role in removing not only suspended sediments from the water column, but can cleanse the water of various pollutants.