What category does koi belong to in Douyin?

Koi belongs to the order Cypriniformes.

The colors of koi include one to several colors, including: white, yellow, orange, red, black and blue (a light gray shade due to the black under the scales). light or shiny. So koi is a common ornamental fish. Although there are endless variations in patterns, the best ones are the small round spots on the top of the head and the stepstone-like pattern on the back. Fish scales may or may not be present; large or small; or they may have wrinkles, like "diamonds".