在同一池塘中，同一养殖周期内放养几种不同品种和不同规格的鱼，称为鱼类的混养。实践证明。鱼类混养是提高养鱼产量的有效措施。而根据鱼类生活习性、鱼类食性和坑塘类型养鱼则是鱼类混养取得成功的关键。从鱼类的生活习性上看，大致可分上层、中下层和底层鱼类三类，鲢鱼、 In the same pond, several different species and sizes of fish are stocked in the same breeding cycle, called fish polyculture. Practice proved. Fish polyculture is an effective measure to raise fish production. According to fish habits, fish feeding habits and pond type of fish farming fish polyculture is the key to success. From the fish’s habits point of view, can be divided into the upper, middle and lower classes of fish and three categories, silver carp,