Karasu: The Koi Pond Phantom

Karasu. The Crow. Pronounced kar-rah-soo, it gets its name because of its deep, jet black color. An almost completely black koi, this Kawarimono class koi will often have some different colors on the ventral area. Red, orange and yellow are the most common colors, and in some rare instances, white. But as they are usually only seen from above, this interesting feature of the Karasu often goes unnoticed.

Unlike some other koi with black markings, the good news is the sumi of a Karasu rarely fades with time. The black is there for good.

It is important to note what Karasu are not: Karasu are not Magoi. Magoi, the progenitor for the brocaded carp, is a dark, drab koi, devoid of bright colors. Although Magoi are dark-colored koi, they are not the true black that Karasu are. Against lighter backgrounds, Magoi will demonstrate a more dark brown color that looks black against darker backgrounds. It doesn’t matter how light the background is for a Karasu; they are black.

Karasu Symbolism

The color black automatically evokes a range of visceral reactions that can be based on cultural tropes or personal sentiment. It’s evil or it’s menacing. It’s Death and it’s the devil. But it’s also the color of seduction, power, elegance, and authority. It is a singular color, able to exist on its own without judgment.

In fact, the Japanese believe black koi to be good luck, an omen of prosperity, bringing wealth and fortune to the owner. Black, and by extension the Karasu, absorb the negative or malevolent energy in a pond, thereby ridding the pond of bad luck and so leaving the positive energy and good luck behind.

There is so much symbolism around the crow. They are raucous, free-spirited, and mysterious. The crow is a harbinger of death and purveyor of fortune. Crows have their own mythology and legend in many different cultures. The Vikings believed them to be a sign of good luck and would use them to navigate on long voyages. The Ancient Greeks believed them to be a prophetic symbol and a sign of good fortune.

Karasu Origins

The Karasu has also been bred to be black. When and how they first came into being is a story for debate (as often is the case in this hobby!). Some claim that Karasu have been around for many years, while others insist that they were a post-WWII phenomenon that was precipitated by the fallout from the nuclear attack.

As expected, the Karasu divides opinions amongst koi lovers. If you talk to more than a few koi kichi, they will tell you that there’s not really much to tell about this type of koi fish. It’s black. It can be either wagoi (with scales) or doitsu (scaleless), and it comes in both types of finnage, butterfly or regular fins.

In fact, some koi keepers marvel at the fact that anyone would be interested in keeping a karasu at all. Why pay top buck for a fish that you hardly ever see—especially if you have a black liner in your pond?

And they are so plain. Outside of the splash of color on the belly—which you also never see!—they are just plain black fish. The only time you will see them, is when they are at the surface, and there’s no guarantee then, either.

But there are others who are mesmerized by the elegant black beauty of the Karasu. They are enigmatic. Whereas an Ogon can all but be seen from outer space with the naked eye, leaving nothing to the imagination, the Karasu darts in and out of sight, making the casual observer question if they saw what they thought they saw. And when the sun does reflect off the black, it can be mesmerizing.

In recent years, however, this black-hued koi has become increasingly popular in koi kichi ponds. There is beauty in the subtlety of the Karasu.

They are true black koi, and the appreciation of the koi’s simplicity is often something that becomes more pointed as koi keepers’ tastes develop over time. The contrast that they offer is the yin to the colorful yang of the more traditional style of koi.

What To Look for in a Karasu

Because Karasu is a monochromatic koi (at least when viewed from above), the color itself becomes extremely important. The black should be deep. The deeper the better. It has to be blemish free and a vibrant black. Any imperfection will immediately be visible against the black background.

The same goes for the finnage. It should not be torn or ripped. The fins should have no color at the tips or fanning out through the fin.

The color on the belly, if any, should be minimal. Again, red, orange or yellow are the most common colors found on the underside of a Karasu. Occasionally, there will be a white belly, but it is extremely rare.

The area around the eyes should also be black. There can’t be any imperfections in the coloration because it will be immediately apparent, detracting from the uniformity and depth of the black.

Karasu keepers also remind those thinking about adding a crow to the pond that clear water is a huge bonus for seeing this type of koi. It is much easier to miss a Karasu in murky water.

A well-cared-for Karasu can reach three feet in length. They also tend to be very easy going koi. Feeding Karasu color-enhancing food, although seemingly a good idea, doesn’t do much for their overall hue.

Whatever your thoughts are about the spectacularly black Karasu, a healthy, happy monochromatic koi adds an interestingly different dynamic to any pond. Think of a lustrous Platinum Ogon and a jet black Karasu side by side. They are very much like the Yin and Yang in a koi pond. And if nothing else, a Karasu and the flash of midnight it looks like in a pond, is a terrific conversation starter.