Japanese koi fish
Koi are generally peaceful. They may, however, pick on slow moving fish such as fancy goldfish. Since they are cool water fish, they generally should not be housed in an aquarium with Tropical Fish.
Koi can be overwintered in the pond in most areas of the country if the water is at least 3 feet deep. They are not as cold tolerant as the goldfish, so keeping them indoors would be advised in very cold climates. Koi can be kept in a large aquarium set-up in a cool basement or garage until the spring, then returned to the pond.
There are many different color variations of koi available. Their average life span is 60 years.
We hope this has given you a better understanding of Nishikigoi and removed some of the complexity around the different categories. Naturally, there is always more to learn about Koi names, terms, differences and developing strains.
If you would like to become more conversant with the different Koi terms, you will find ample information in our alphabetic Koi glossary under the drop-down Koi menu above. As a reward for learning more about this beautiful species, you will also find some gorgeous images of award-winning Nishikigoi on the glossary page.