There are four reasons. First, the water in the fish pond is soft and weakly acidic. This kind of fish, especially CYPRINIDAE fish, is not firm in meat quality. Second, there are too many feed additives, fish grow too fast and the meat quality is slack. There is too little protein in the feed or bait, and the muscles of fish are underdeveloped, not tight and the meat quality is slack. The variation of the four fish is the same as the first three cases, and the meat is cooked like tofu brain. At present, the relevant aquatic products departments are deliberately breeding this fish in order to dilute its tenderness.