Catfish, also known as long-bearded silver carp, sticky fish, pond lice fish and raw fish. This kind of fish is characterized by no scales, sticky body surface, flat head, wide mouth and four whiskers on the upper and lower jaws. The best eating season for catfish is between mid-spring and mid-summer. Catfish is not only as nutritious as other fish, but also has tender meat, delicious taste, less thorns and easy digestion, which is especially suitable for the elderly and children. Catfish are found everywhere on seven continents except Antarctica. Some catfish are marine fish. The size of this kind of fish varies greatly, including the world's largest freshwater fish, the European catfish, which is 5 meters long and weighs 330 kilograms. There is also a very small parasitic catfish, which is the smallest vertebrate. The adult is less than 10 mm. This order includes 35 families, but the taxonomic table is still changing, with about 2,855 species, equivalent to14 freshwater fish and/.