Koi fish

These fish were selected a long time ago in China and Japan by powerful dynasties who wanted frisky colourful fish in their artesian ponds and palaces. During the Chinese Qing dynasty, Koi fish species greatly increased and in Japan the breeding of Koi fish became a real business for fish lovers.  

In the Japanese language, Koi means love and affection; this was how the Koi fish turned into a symbol of friendship and in other Oriental countries the symbol of kindness.  

Koi fish vary in colour, they are most frequently white, black, red, yellow, beige and blue. Their colour is not always good for them, as it makes them easy prey. They can sometimes live for 30-40 years.  

This type of fish will survive winters even at low temperatures by adopting a lethargic condition. They need a lot of oxygen, so their aquariums must contain over 7 mg oxygen/ litre, if this level drops it can become dangerous for the fish, it will prevent the fish developing properly and from feeding adequately.

The optimum value of the water’s pH is 7.5. The feeding process differs from one growing system to another. Normally the fish are omnivores but they can also eat combined fodder. When free, they eat all types of organisms like Daphnis or organisms from the bottom of the lake and also aquatic plants.  

When they are in captivity, and are being bred for sale and the nurture’s composition can significantly change their colour.     

They accept their food in a large spectre of temperatures, 6 up to 28 Celsius degrees. 

The reproduction process takes place in May to June but through light correction (photoperiod) and temperature you can obtain several generations in the same year. 

This type of ornamental fish is not sexual dimorph (the figure differences among the two genders). The sexual maturity shows earlier in male fish (after 2 years) and female fish can reach sexual maturity when they are 3 or 4 years old. 

They can produce 100.000 fish eggs/ kilogram.