Koi carp (Cyprinus rubrofuscus), or simply koi, are ornamental varieties of the common carp native to East Asia. The history of koi carp dates back centuries, primarily associated with China and Japan.

1. Ancient China: Koi carp are believed to have originated in China, where they were initially bred for food around 2,500 years ago. Over time, Chinese breeders began to notice color variations in carp populations and started selectively breeding for these unique colors. These early ornamental carps were highly prized and often gifted to nobles and emperors.
2. Introduction to Japan: Koi carp were introduced to Japan around the 5th century, primarily for food. In the early 19th century, Japanese rice farmers in Niigata Prefecture began selectively breeding koi for color. Niigata’s harsh winters forced the farmers to move their koi to deeper ponds, where they could better observe the colors and patterns on the fish.
3. Modern koi breeding: In the early 20th century, the hobby of koi breeding expanded beyond Niigata, and new color varieties were developed. The first koi show was held in Tokyo in 1914, helping to popularize the hobby across Japan. By the mid-20th century, koi carp had become a symbol of Japanese culture and were prized as living works of art.
4. International interest: Koi carp gained international attention following World War II, when American servicemen stationed in Japan brought the ornamental fish back to the United States. Since then, koi carp have become increasingly popular worldwide as both a hobby and an art form. Today, there are numerous koi varieties with distinct colors, patterns, and scale types, reflecting centuries of selective breeding.

Koi carp have a long and storied history, evolving from a food source to a highly prized ornamental fish. Their rich cultural significance in East Asia, particularly Japan, has led to their global popularity and appreciation among enthusiasts and collectors.