Though two oysters may be alike in size and quality, the one with a smooth, regular shell brings a higher price in the market than the rough, irregular one, which is ugly and hard to open. So growers give considerable attention to breaking up the clumps upon which the spat is attached, thus giving the individual more room, and in the end making a crop superior in form, size and flavour.
The taking of oysters for market thins the bed, and improves the conditions under which the young oysters are living. With clutch of scallops and jingles, growth of the new shells is a force that helps to break apart the substance to which they are attached. Distorted shells improve in shape when the cause of their dis tortion is removed.
Flavour and Fat.— Transplanting has a marked effect upon the rate of growth and upon the flavour of an oyster. These considerations are vital. There is a year's difference in the time of bringing an oyster to market on the two sides of Long Island. As many as possible are taken to Great South Bay from the Sound for this final spurt. Two-year-old stock averaging one and three-eighth inches long brought from the Connecticut shore in May attain three inches by November. Cleaner water and more room make better-shaped shells, fatter and better-flavoured oysters — hence a higher market price. " Blue Point " oysters are all grown or finished in Great South Bay, though Blue Point is but one of many villages that supply the New York market with this popular brand.
The famous French "green oysters" of Marennes are care fully fattened in ponds containing a green diatom whose pigment colours the gill fringes to the shade required by an exacting public, and gives the oyster their distinctive flavour. English people and Americans frankly dislike green oysters.
The British oyster market is supplied from beds about the mouth of the Thames and off the coasts of Kent and Essex. The Englishman prefers a five-inch "native," five years old. In New York oysters are marketed at from three years old upward.
Oysters are fattened on bran and oatmeal in cellar tanks for the Billingsgate market in London. "The flavour is all but lost in the fat." Experiments prove our oysters to fatten and 429 The Oysters improve in flavour by being liberally supplied with fine corn meal.
This is not practicable; the natural food supply brings the oyster to prime condition, and extra fatness is not demanded by the American market.
The best fattening grounds are often found near the mouths of rivers, in brackish water. It is true that by reason of the pollution of streams by sewage, oysters are contaminated, and typhoid and cholera sometimes develop in persons eating these oysters. "Oyster scares" are periodic outbreaks that for a time check local demand. The laying down in clean water of oysters from muddy beds greatly improves their appearance and flavour, by the thorough washing it accomplishes.
The Oyster's Enemies.— It is calculated that an infant oyster has but one chance in one million one hundred and forty-five thousand to grow up. Fish devour the larva in great numbers. Settled comfortably on the shell or stone that is to be its support for life, and shielded to an increasing extent by its own shell, the oyster may bid farewell to many fears that beset its free swimming infancy. But enemies are present in great variety and numbers still. A freshet may cause deposits of mud that smother them; the currents may shift the sand just enough to bury them. Crabs many times devastate an oyster bed, as if by concerted action, crushing all young shells up to a year old with their powerful pincers. The starfish, ray and octopus do great damage. Drills (Urosalpinx) and dog whelks (Nassa) are enemies which bore the shells with their rasping tongues and suck out the soft parts, leaving the tough remains for the scav enger crabs and whelks. The moon shell (Natica) and pear conch (Fulgur), are charged with similar deeds, but they are not such oyster specialists as the well-hated and hotly pursued drills.
Fish consume young oysters until the shells are hard enough to resist their horny jaws. The drumfish and sheepshead menace the beds about Long Island. Menhaden and alewife are in this same predatory class.
One of the most insidious enemies is the boring sponge which honeycombs the shells so that the oyster is exhausted with seal ing up punctures with new shell deposits. Often these shells crumble. They form stations for the attachment of sponges and hydroids, which smother the oyster, and rob it of food.