If good bottom is found, the larvae secrete fluid that cements them permanently to the bottom. Larvae settling out in soft mud or other unsuitable areas usually do not survive. Once settled, the developing oysters can become sexually mature within a month and then contribute to another generation of oysters in a very short time. Interestingly, oysters sometimes change sex after spawning. In particular, young males often become egg-producing females.
Oysters eat by filtering food from the surrounding water through their gills.
Under ideal conditions an oyster can pump 5 gallons of water an hour through its filtering apparatus. The Environment Oysters are bound to one spot after they settle and are at the mercy of the water brought to them by currents and tides. Oyster drills alone are capable of killing 85 percent of the young oysters on a reef. Furthermore, oysters can be smothered by sand and silt from dredging operations or extremely heavy storms. They close the reefs to harvesting when bacterial counts indicate that disease-causing organisms are above acceptable levels.