Oyster is one of the most resistant aquatic animals. In the past 200 million years, the changing environment in intertidal zone has exercised the strong resistance of oysters to temperature, salinity, common pathogens in the open air and sea. When the ebb tide comes out of the water, it can endure the hot and dry weather in summer and successfully adapt to the freezing weather in winter.
In natural groups, most oysters are hermaphroditic, and a few are hermaphroditic. Oysters can also "degenerate" spontaneously, and the same individual shows different sexes in different years or under different environmental conditions.
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Worldwide distribution, China is rich in oyster resources, which is the hometown of oysters and has a long history of using oysters. As early as more than 2,000 years ago, residents in some areas along the southern coast of China mastered oyster culture technology.
There are oyster production bases in Bohai Sea, Yellow Sea, East China Sea and South China Sea, and the main producing areas are Fujian, Guangdong, Shandong, Guangxi, Liaoning and Zhejiang. Among them, oyster is the most important breed. ?
More than 100 kinds of oysters have been found, which are produced in almost all coastal countries. Japanese oysters are the same as those in Otawa and China. European and American oysters mainly include edible oysters, American oysters and European oysters, and the total output ranks first among shellfish. China began to cultivate oysters with bamboo in the Han Dynasty, and it has a history of more than 2,000 years.