The eel is the meat or the whole body of the eel, Anguilla anguilla. Eel is one of the fishes in the family of eel, which is one of the fishes in the suborder of eel of the order of eel of the order of eel of the order of eel of the order of eel of the order of eel of the class of eel. Like a snake, scales are small, buried in the skin, generally produced in the salt and freshwater junction of the sea. It is mainly distributed in the Yangtze River, Min River, Pearl River Basin, Hainan Island and rivers and lakes in China. There are 18 species of eels in the world, including four families in Taiwan: Japanese eels, perch eels, Celebes eels and short-finned eels, but only the Japanese eels are the most abundant, while the other three are rare. They have survived on earth for tens of millions of years, but our understanding of them is only in the last few decades. For example, it was only in 1991 that their true spawning grounds were discovered. The sex of the eel is controlled by environmental factors and density, and when the density is high and there is not enough food, the eel will turn into a male, and vice versa, into a female. In the rivers of Taiwan, eels are mostly females because they are few in number. [1]