Ancient koi “Hanako” 

”Hanako” is a famous episode that symbolizes ”Koi live long”. Hanako, who lived in a pond in Higashi Shirakawa, Gifu. Because it was estimated to be 223 years old based on the number of rings on her scales, so it became a hot topic of discussion，even included in the Guinness Book of Records published in 1983. However, this age is now considered to be incorrect. The age of 223 years seems to have arisen from the misunderstanding that the ridges carved into the fish’s scales as they grow one each year, similar to tree rings. In fact, many ridges form in a year, especially when the people are young. This is because the fry and young fish grow faster and their scales become larger. Humans also grow the most in height from birth to one year of age, and most of their growth stops by the age of 18. Similarly, koi do not continue to grow throughout their lifespans, so their scales naturally stop growing at a certain age. Determining the age of Koi by scales is difficult for Koi that have passed their growth stage.

The actual lifespan of Nishikigoi is said to be around 30 to 40 years, It depending on the environment in which they are kept. However, the period during which it retains its ornamental value is shorter than that. The qualities of the koi, its environment, the love of its breeders…all are essential for its beauty.