Herring is a kind of blue-colored fish, mainly distributed in the plains south of the Yangtze River in my country, and sparse in the north of the Yangtze River; it is an important fishery resource in the middle and lower reaches of the Yangtze River and lakes along the Yangtze River and the main breeding object in lakes and ponds , Is one of the "four major home fishes" in freshwater farming in my country. In addition, it is commonly known in Anhui as "Wu Hun", "Hei Hun" or "Snail Hun" because of its black body and its preference for eating snails. China's main freshwater fish farming objects. Distributed in major water systems in China, mainly produced in the plains south of the Yangtze River. Fish gall is poisonous. "