The Koi is a highly prized, long-lived show fish. A large, healthy Koi can sell for as much as 250,000 dollars. Their beautiful colors and peaceful attitude make them very attractive to all fish lovers, especially the experienced aquarists. Raising Koi is a joy that every fish lover should experience.

The Koi is a peaceful fish. If kept in groups, Koi will school. They will not bother other similarly sized fish, but Koi will eat smaller fish. Most Koi like to dig through gravel, which can cause plants to be uprooted. Live plants should be potted and plastic plants should be well weighted. Koi are best kept in large ponds that are a minimum size of 1000 gallons, though younger individuals may do all right in an aquarium, though this is not suitable for a permanent habitat.

At maturity, Koi can reach a size of one meter. Koi will grow roughly two centimeters a month. While Koi vary in size and color, they are almost always beautiful. They are described by the Chinese as "swimming flowers". They resemble large guppies. Most Koi have an average life span of 60 years. There are several varieties of Koi including "Showa", "Sanke", "Kohaku", "Ogon", and "Utsuri".

Koi have a long history of show and breeding. Koi were first recorded in history in a Chinese book written during the Western Chin Dynasty, between 265 and 316 AD. These Chinese fish may have been early example of carp, but the Japanese developed the Koi we know today approximately 200 years ago. The Japanese developed the bloodlines that define the standard in which Koi are judged. Since then, they have been breed into many different varieties and have spread from the orient to around the world.

Being so large, Koi need to be kept in very large aquariums or ponds. They will do best in water with a temperature between 68 and 75 degrees fahrenheit. Their water should be hard and have a slightly alkaline pH, between seven and eight. Koi should be fed a variety of foods. Vegetables, such as spinach, zucchini, peas and lettuce are great for the Koi. Koi should also be fed live foods, including bloodworms, tadpoles, glass worms, earthworms, brine shrimp, daphnia, tubifex worms and small fish. Frozen, tablet and pellet foods will also be accepted.

Koi can be bred, but they require great amounts of space. A pond of 50,000 to 200,000 gallons is recommended to breed Koi. Koi will be able to breed when they reach an age of three to four years. A female Calico Koi will lay several hundred thousand eggs when spawning. Male Koi can be distinguished by their larger heads and longer pectoral fins.