Koi

Koi fish are a type of carp {Amur carp (Cyprinus rubrofuscus)} kept mostly in outdoor gardens and ponds. Many koi fish are kept for decorative purposes, although some breeds are eaten. They originated from Asia, mainly Japan.

Size

There being more than 100 varieties of koi fish, the sizes differ per breed. However, most koi measure 12 to 15 inches in length, with some growing as long as 36 inches. 

Adaptability

Koi are quite hardy but still prefer temperatures of 59-77°F. They are highly adaptable and have been introduced in so many parts of the world apart from the continent of Antarctica.

Behavior

They are happy fish even in their swimming patterns and how they respond to handlers. They can even remember their names and the faces of their handlers. Each fish has its own unique personality, and hence the level of aggressiveness differs among them.

Interesting Facts

Koi are among the longest-living fish, with some living for more than 200 years. Given their innate behavior to stir up the substrate, they are used to control insects in ponds on golf courses and in other areas.