I just bought some Koi fish for my pond. These are Amur carp fish with different colored variants.
They are amazing fish i have heard the live up to 30 years or something like that 
The koi are popular in Japan where they recognize many varieties.
Do you know how old was the longest living koi fish?
Koi
Koi is an informal group of the colored variants of "C. carpio". Several varieties are recognized by the Japanese. Koi varieties are distinguished by coloration, patterning, and scalation. Some of the major colors are white, black, red, orange, yellow, blue, and cream. The most popular category of koi is the "Gosanke", which is made up of the "Kohaku", "Taisho Sanshoku", and "Showa Sanshoku" varieties.
History.
Carp are a large
throughout Japan. From this original handful of koi, all other Nishikigoi varieties were bred, with the exception of the Ogon variety (single-colored, metallic koi), which was developed relatively recently. 
The hobby of keeping koi eventually spread worldwide. They are now sold in many pet aquarium shops, with higher-quality fish available from specialist dealers. The collection of koi throughout the years has become quite the social hobby for many who have ponds. It is also common for hobbyists who are passionate about their koi