I love fish. Several years ago, I installed a pond in my house, with plants, a heating system and a water filter, I got two koi fish. I looked at their behaviour for a few days and one thing that struck me was that they always seemed to want to swim against the current generated by the water filter.  Why would they do that? This became even more curious to me when I heard the legend of the koi fish.

The koi fish is also known as koi carp, or simply koi, and is native to Japan and China, although it now lives all over the world. We have probably seen them in ponds and oriental-style gardens. They are brightly coloured fish (red, yellow, orange, silver and others) that can measure 50 to 90 centimetres and live up to 65 years, under favourable conditions. But what is the legend about the koi fish?

There are different versions of this legend. One tells of fish swimming in the Yellow River in China. They all swam in the direction of the flow until one set himself the goal of swimming in the opposite direction and up the waterfall. Many others took up the challenge, but it was very difficult, as not only the waterfall pushed them down, but also the demons that guarded it. This continued for as long as it took until one of them managed to jump a little further and reached the top. The gods, observing the perseverance of this fish, decided to turn him into a dragon as a reward for having achieved his goal. Since then, it was said that the fish that managed to climb the waterfall would become a dragon.

Today, these fish are considered to attract prosperity in business and academic life. They are also considered a symbol of perseverance, as it is said that the koi’s ascent to the waterfall is tantamount to success in life.