The different varieties of koi carp are distinguished by color, decoration and quality of the scales. The main colors are white, black, red, yellow, blue and cream. Although the various combinations of colors are innumerable, scholars have identified the summary categories of classification of the different fish.
New varieties of fish are also currently being produced. Ghost koi has been developing since the 1980s and has become very popular, especially in the UK. At the same time there are also hybrids of wild carp and Ogon koi, which are distinguished by the metallic color of the scales.
Koi were developed from the common carp in China during the Jìn dynasty. We have the first news of these carp, known by the generic name of koi, starting from the fifth century BC. since they are used in aquaculture. The common carp was introduced to Japan via China in the 15th century and from there began the classification and production of carp with different colors.
The various types were brought together in 1914 in Tokyo where the first of a series of annual exhibitions on the subject was held.
Koi and their long life
Koi are omnivorous fish and their diets usually include peas, lettuce and watermelon.
Equipped with a certain memory, they are able to recognize the people who feed them and the place where they usually receive food to such an extent that they can be trained to take food directly from the hands. The digestive system of koi decreases its activity during the winter period until it almost stops and consequently the amount of food ingested in this season decreases.
It is not recommended to feed carp when the water temperature drops below 10 ° C. Koi are also among the longest-lived fish in existence, they can live up to 80 years without showing signs of aging: if eaten, the meat retains the typical savory flavor characteristic of Middle Eastern farming even after several years from killing.
Not showing signs of aging is currently being studied by scientists for implementation in anti-wrinkle creams. A famous scarlet koi named Hanako lived 226 years. The age of koi can be deduced from a laboratory analysis of a fish scale and for Hanako this study was done in 1966. Hanako holds the longest-lived fish record in the world.