Koi are actually a type of carp, and today they're some of the most expensive pet fish in the world. But why? Koi were originally raised in Japan in the 1700s when rice farmers first began ...

“We let the water circulate for a week, then we slowly add in the koi,” he says. They typically come in transparent bags and ...

As the name implies, it's an outdoor pond populated by koi fish, a colorful, domesticated carp that adapts well to a variety of spaces. Originally domesticated in China, these beautiful fish ...

Koi fish are what you might call a happy accident. In the 1600s, Japanese carp farmers began noticing unusual color variations among the fish. "The popular koi fish of today are actually ...

Koi diplomacy is back with Japanese nishikigoi, or ornamental carp, set to return to the lucrative Chinese market after a nearly year-long hiatus. Sources have confirmed that Chinese authorities ...