How long do koi live?

 This is not an easy question!  Koi have a hard, and possibly short, life ahead of them when entering the new pond of a new koi keeper!  In some cases the answer to the question can be – about as long as summer lasts!  And unfortunately this has been the case for much of the history of koi in America. But with educational efforts by ZNA and also by putting the emphasis on koi appreciation (IE the real value of a special individual fish), the strives made to understand the needs of koi and the husbandry of koi have improved the statistics on the life expectancy of koi in America.  

   In the 1990s decade of the koi show, the average life span of koi probably moved into the 5- 8 year mark. This is however misleading in that the new koi keeper was still losing koi prematurely and they outnumber the established koi keeper 20-1. So even though many ZNA members have koi that are 20 years old, this statistic is swamped by the numbers of beginners and their ‘learning curve’ experiences. And we must consider that many koi die from accidents in their prime which can skew the numbers. Loss of electricity, motors failing,  ponds draining, chlorine accidents, over dosing accidents, predators, accidently poisoning and introduction of disease and parasites to an established pond- all pull down our average lifespan numbers dramatically.

    Many years ago we were told by some Japanese dealers that koi in Japan live to be hundreds of years old. This was hard to hear for American hobbyists that struggled to have their koi live a single year! Stories of famous koi such as ‘Hanako’ living 217 years were quite appealing to the prospective koi keeper of the 1980s. So it was hard to learn that as charming as that story was, it was just that- a story. Even in Japan, ‘stuff happens’ to koi!  And there are exceptions to rules but not 217 year old exceptions!

   The truth is, individual koi tend to live, all things being equal, different periods of time. Not unlike breeds of dogs, which can vary from 7 years for giant breeds like great danes to toy poodles that can live 17 years, koi can also have normal life spans that vary widely.  Wild type koi types (solid colored koi with primitive colors of black, red or yellow) tend to live a long time. I have known hobbyists for instance that have pet koi for some 30 years.  But in the show varieties such as Gosanke, the realistic life span is probably 14- 23 years old. This is likely their normal or natural life span and assumes that koi that do die at ages 8-12 are the result of conditions and stress over their lifetimes and then having a single stress event bring their lives to an end.

 We should not ever expect ‘Hanako’ type ages to be achieved in our ponds. But we should strive to make a 20 year old healthy koi a reality. Talk to your fellow ZNA members about the ages of their koi. When you find a member that has koi in the 15- 25 year range, make them your mentor as they must be doing something fundamentally right! 

                                                                                                                           Happy koi keeping. JR