The Koi (”Nishikigoi” for Japanese) are becoming quite popular in the United States for breeding. But only few people really know how and where they came to be. The first Koi resulted from the breeding of the German and Asian carp. After being selectively bred for years, different variations in color and pattern started to show up. The earliest patterns in color were recorded in the year 1805. To this day, thousands and thousands of color combinations and variations can be seen.

Popular colors include yellow, red, white, green, silver, orange, black and blue. There are countless possiblities of color combinations. Each Koi have their own name, and these names are based on their color and pattern. The favorite types may differ, depending on the location and country.

These fish are being raised for sale in various countries, like Japan, Singapore, Israel and the warmer states in the U.S.. The Koi can be purchased at many local pet stores. If they don’t have the stock readily available, they can be ordered. By ordering, the advantage of this is that the buyer will have more options, since they don’t have to pick from the stock on hand. On the other hand, the downside of this is that the buyer will not be able to pick the specific Koi they want to have.

Unlike most of the other fish out there, they will continually grow until they’ll reach the maximum size of their breed (no matter where they’re being placed in). The young are 3 inches long, while the biggest ones can reach around 3 feet or more! Their most common size reach up to two feet long. They have been known to live up to 30 years old under the right conditions, the oldest of which lived up to 233 years!

The Koi are omnivorous, as they feed on meat and plants alike. And this results in the adaptability of their diet. They will eat almost anything that you feed them, no matter if it’s good for them or not. The owner should control their diet, as they have no ability to judge what’s good or not for them, and the amounts that they should be taking on a daily basis as well. The healthiest treats for them are the natural food, such as tadpoles and earthworms, and treats like fruit, veggies, lettuce and bread.

Owners should take necessary precautions when feeding them with beans, corns and grapes, as these food contain an outer casing, which can't be properly digested by the fish if eaten by them. Outer casings of these food should be removed before feeding them to your pets.

The Koi are non-aggressive fish, capable of mingling with other fish like the comet and goldfish. As they are fast eaters, the Koi will eat any fish that they will find smaller, and this could be a problem! They don’t have teeth, which is why it’s quite okay for them to be feed through the hand (which can be a great past time for their owners too)!). For fish lovers out there, Koi breeding is truly a great and fun hobby!