Because of the place of origin and sales and the city according to the information, a body length of only 15 millimeters of young Gan fish can swallow other species of fish fry, a body weight of 15 kg Gan fish, can eat 5 kg carp, which is equivalent to 1/3 of its weight. because of its body narrow and long streamlined, so the swim speed is very fast, encounter other small fish, it will be like an arrow like fast swim, found attack, the frightened fish did not understand the enemy, but the enemy's life habits, the fish is the most important thing is that the fish is the most important thing. Frightened fish have not yet understood the enemy from where, has become its belly, so Gan fish have "fish in the water," the name. Because it specializes in predatory fish, the aquaculture industry is beneficial and harmful, if too many small fish in the water affects the growth of large fish, it can be these small fish "eliminated", so as to purify the fish species in the water, so that the big fish grows well. If the small fish in the water is not much, then the larger fish has become the object of its hunting, thus reducing the production of fish, affecting the income of fish farmers. So also some people say Gan fish for harmful fish. The good thing is Gan fish live in the large surface of the lake and reservoir and river, the number is not too much, so the harm caused to the fish farmers is not too big. The market is different, the price is for reference only.