Gary Turk, age 13, of Huntsville, Alabama, for his question:
How long does it take an oyster to mature?
A mature animal is one that is old enough to reproduce. An oyster develops from childhood through adolescence before he reaches parenthood. He can produce offspring at the ale of two or three years, depending upon where he lives. It takes him much longer to produce a sizable pearl.
Oysters enjoy their lazy lives in the calm shallows by the sea. There are about 100 different species around the world in warm and temperate bays and quiet inlets. Some species produce gleaming pearls and others are delicious, nutritious morsels of food. Most other species have little value. All oysters, of course, are bivalved mollusks – two shelled members of the animal phylum Mollusca.
Life for each generation of oysters begins when the temperature of the water reaches 66 to 70 degrees Fahrenheit. In the warm Gulf of Mexico, egg laying begins in March and :.he spawning goes on through November. The New England oysters begin their spawning in July. Masses of tiny eggs float like yellowish cream in the gentle water. And through the season, one oyster may produce half a billion eggs.
An oyster is fixed to the spot and never moves, even to become a parent. The adult males and females pour separate masses of sperm cells and egg cells into the water. Here and there, a sperm and an egg cell meet by chance. The pair unites and forms a fertilized egg. In a day or so, the egg hatches into a larva oyster, small enough to swim easily through the eye of a needle.
The larva looks like a miniature melon seed wearing a shaggy wig. The hairs are cilia which he waves to propel himself through the water: For perhaps two weeks he enjoys a free swimming life, feeding and growing. Then he forsakes his freedom for a settled life. He chooses a pebble strewn sea bed, the piling of a pier or some other submerged, solid surface. Then he secretes a tacky substance and cements himself to the spot he hopes to occupy for the rest of his life. The balmy water washes diatom food into his open mouth and the lazy fellow grows at a great rate.
If he lives in the warm Gulf of Mexico, he feeds and grows through the entire year. But if he is a native New Englander, he does not eat and grow during the cool winter season. These months of resting delay his progress toward maturity. Oysters of tropical and semitropical seas are mature and ready to hand on life at the age of three years. Osyters of cool winter waters, as a rule, are mature at the age of four years.
Edible oysters are pampered and tended by fishermen. The settled youngsters are called oyster spats until they become two inches long. Many spats are uprooted and placed to resettle themselves in more suitable locations. After three or four years, they are mature and ready to be harvested for the market. Pearl oysters are left undisturbed long enough to grow their secret treasures. After seven years, rivers bring them up to be opened for their pearly prizes.