Koi Fish History, Facts, and Their Colour

Koi Fish History From 17th Century to 20th Century, The Modern Era

Koi fish breeding started in earnest in the 17th century, in Japan, a place called Niigata Prefecture. This is a region renowned for its production of rice.

The farmers of this place noticed the dismally gray carp. The reason is the koi fish would generate offspring with different colors and body patterns. After due research and study, the farmers were capable of establishing so many different varieties of colorful koi fish

Fast forward two hundred years. Now it’s the 19th century, and there’s an explosion of koi farmers breeding these fish. New color varieties are being developed in the region.

If you’re at all familiar with koi, then you may recognize the variety of Kohaku developed during this time period.

This once drab fish traditionally used only as food – became a wildly popular ornamental fish. In fact, it was fast becoming the era’s “fashion statement.” Eventually, this koi became known as the “fish of the nobility.”

If we talk about koi fish history, koi has been a symbol of masculinity and strength in Japan. These fish are popularly known in Japan as “warrior’s fish.” (This doesn’t get so much masculine than that!)

However, at that point in history, koi didn’t have the international notoriety they enjoy today.

Even at the beginning of the 20th century, their fame and admiration were confined to the Niigata region of Japan.

But that soon changed. In 1914, an exposition was held in Tokyo. Some of the most beautiful koi of the Niigata region were transported and shown at the expo.

Listen to the rest of the story. I confirm that you’re well ahead of me by now. The koi’s appearance in Tokyo marked the first time this colorful fish had ever been seen by people outside of the village region.

The people went “koi-crazy. Some of the best specimens were gifted to “The Crown Prince Hirohito. It wasn’t long before the entire country was talking about koi. Soon, their popularity spread to other areas of the world.

As the fish’s popularity grew, the major pedigree lines became established. This provided for the development of even more varieties. During the twentieth century, the varieties of koi exploded.

The most skilled of the breeders use a combination of traditional techniques and modern genetics, bearing in mind the historical line of the fish. Every year, more varieties are developed and presented to the public.

You’ll surely love the fact that koi live a relatively long life.

A lot of koi fish keepers feel proud in the fact that they are continually keeping koi fish as a tradition that began thousands of years ago.

If you happen to be a Japanese breeder of certain pedigree lines, your fish could be especially prized. Many of these fish command large amounts of money when sold today. It’s common for some breed specimens to value for upwards of $15,000 to $20,000.

It wasn’t until the 1950s, though, that koi became popular in the West. And it really wasn’t until the 1980s that koi really sparked the imagination of America. That era experienced a rise in the interest in ornamental garden ponds, and with it, a natural interest in koi.

And that brings us to today. More people than ever before are discovering the beauty of these irresistible fish. And you, obviously, are one of them.

Koi Colors

Koi Fish History, Facts and Their Colour
Koi Fish History, Facts, and Their Colour

A reference and guide to Koi fish with color was found in a Chinese book. This was as far back as Western Chin Dynasty. For those of you who aren’t up on the dates of the royal houses of China (and few of us are!), that dynasty lasted from 265 to 316 AD.

This special ancient book mentions carp of wide color variations, which includes blue, black, red, and white. The question appeared is – how exactly did the koi fish develop their colors?

Did humans interfere with Mother Nature via deliberate breeding techniques artificially? Or did these koi fish spontaneously mutate into various colors?

In my opinion, probably all these questions will never be answered to anyone’s full satisfaction.

One thing is very clear that the Japanese people took a proactive view of some selective breeding. They became the undisputed leaders in breeding koi and still are today.

What Gives Koi Their Brilliant Colors?

While we speak about the color of koi, we should not forget koi fish history of their color and breeding. Why genetic breeding, of course! But beyond that, physiologically, the colors of the koi are really a function of the pigments within the fish’s skin. The type and distribution of these pigments determine the fish’s color and patterning.

Specific cells actually contain very small sacs of pigment, which scientists refer to as chromatophores. These sacs are capable of holding more than one type of pigment, including one called melanin or black and others called carotenoids. It’s the latter pigments that provide a brilliant variation in color.

Koi also have cells called indocytes that contain something called guanine crystals. These crystals give the fish’s skin a shimmery gold and silver metallic appearance.

If you had the chance to view these cells through a powerful microscope, you would immediately notice that the chromatophore cells appear to have highly branched processes, which are ultimately connected to their nerve fibers.

This is the key to their ability to change color. If a koi is stressed because of illness or the poor quality of water, it may change to a lighter or a darker shade. All that’s required for this feat is the movement of the pigment granules inside the cells.

If the pigment shifts to the center of the cell, the fish turns a lighter color. If the fish turns a darker color, then you know the pigment has moved to the outer areas of the cell.


Dibyajyoti Bordoloi is the creator and author of FishCampRehab.com, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.