This beautiful fish is a variety of the Amur carp. The word "koi" is a Japanese word for carp. Koi are bred for ornamental purposes. They're kept in outdoor pools named Koi ponds. There are many varieties of this fish different in coloration and patterning. Some of the most typical colors are white, black, red, orange, and yellow. Although this hobby comes from Japan, it is nowadays spread almost worldwide. The most popular variety is definitely Kohaku. There are already more than 100 varieties of Koi that are classified and thoroughly described.