Coy fish come from the Japanese word, Koi, which means carp. They are highly popular fish in Japan and China. Coy fish originated in the Aral, Caspian, and Black Seas in Eastern Asia. They are now a highly valued pond fish, although they were once considered to be a food fish. In the 1800s, Japanese farmers started to breed the coy fish for their colors, and they had soon spread around the world as an ornamental fish.Coy fish are a cold water fish that can survive in just about any location. The only place they don’t live is in Antarctica. You can buy coy fish in most pet stores. They usually inhabit garden ponds instead of aquariums because of the amount of water needed for them to stay healthy. In cold climates, the water depth needs to be down to at least 4-½ feet.