The difference between spring fish and roasted fish lies in the variety. Polychun fish is a deep-sea fish native to Japan, belonging to Cucurbitaceae of Cucurbitaceae, also known as Lepidoptera and Cucurbitacea. Because there are many fish eggs in the belly of female fish, it is named Polychun. Yellow crucian carp (Carassius auratus) is a fish of the genus Carassius, also known as Carassius auratus, Bokou, Youkou, and roasted fish. Distributed in dry Indian Ocean and western Pacific Ocean. It is produced in South China Sea, East China Sea, Yellow Sea and Bohai Sea. It can be captured all the year round, with spring and autumn as the peak season and concentrated output. Inhabits in the shallow sea area where the water depth is less than 4- 13 meters and the water flow is slow. The optimum temperature is 5-28 degrees, and it is carnivorous. It mainly eats planktonic crustaceans, as well as sagitta, fish eggs and jellyfish.