|
|
But that's only the "half shell" of it. When the coastal waters reach a certain temperature during the summer months, the Pacific Oysters start romancing each other rather indiscriminately on a almost unbelievable scale. One female can produce 100 million eggs and catapult them out into the water. A male will do the same with a far greater number of sperm. Somewhere the sperm meets the eggs and countless oyster larvae develop. Although the majority will end up being "lunch" for a vast number of natural enemies, many will survive and settle on some rock or shell to become "oyster babys" (so called "spat"). There's also never a shortage of males or females, as oysters are hermaphrodites to boot. Living comfortably in its mother of pearl palace inside, it's thick insulating shell casing presents a formidable fortress to just about anything that creeps, crawls, walks, swims or even flies. Native to Asian ocean waters, this species is likely to have been around for more years than can be displayed on many pocket calculators. It comes as no surprise that the Pacific Oyster is the darling of countless oyster growers in many parts of the world. That Pacific Oyster on our plate carries a Japanese, Chinese, American, French, Canadian, Irish... - even a German passport by now. As humble and simple this oyster overtly appears, Crassostrea gigas is nonetheless a first class evolutionary success story and a respected world citizen by now. Internationally, no other marine animal species is cultivated on a grander scale. In 1996, the Food and Agriculture Organization of the United Nations (FAO) rated the Pacific Oyster as #2 worldwide in terms cultured aquatic production (surprisingly, kelp is #1). Mankind, qualifying itself of course as a far greater evolutionary success story and unquestionably the most powerful predator ever to roam this planet, thins the ranks of the Pacific Oyster to the tune of just about 3.000.000 tons per year. Other oysters had different evolutionary
"ideas." Take the noble European Oyster (Ostrea edulis)
for example: Species of another oyster family (called Spondylidae) evolved into fortresses bristling with spears, certain to turn off a great number of natural oyster predators. Unlike many other bivalves (like clams and scallops for example) "running away" was, oddly enough, never part of the evolutionary survival recipe of the oysters. They are the classic "home bodies of the ocean." They actually have no choice but to stand their ground when danger nears. From childhood on they're stuck right where they are in plain sight on the ocean floor for as long as they live. Barring storms (and mankind nowadays of course) that may move some of them involuntarily, they'd surely be a postmaster's dream: Never a "change of address."
|
||||||
---|---|---|---|---|---|---|---|