Three scales. According to the information on the inquiry website, soft-shelled turtle is a rare fish, so it is even rarer in the market, and the price will be higher, while the price of perch will be more stable. Three scales refers to mirror carp, which is a kind of fish of CYPRINIDAE, with a stout body, flat side, raised head and back, small head, big eyes, two pairs of jaws, short gill rakes and a medium triangular arrangement; Tail fin fork; The scales on the body surface are large and arranged along the edge, and there is a complete scale line from the front end of dorsal fin to the head.