Koi fish, 25 cm, weighs three and a half pounds. A normal well-developed koi fish is100g. Koi fish is an online buzzword and a cultural phenomenon. Koi fish is a kind of high-grade ornamental fish, which is rich in ornamental value and deeply loved by people. In modern times, it refers to everything related to good luck, such as people with good luck or things that can bring good luck.