Shusui Koi Fish

Distinguishable Ways to Identify These Unique Fish

Shusui koi fish are perhaps the most unusual koi variety in appearance. They add a dash of novelty to any koi pond with their striking appearance.

The Shusui koi first appeared in 1910 when an Asagi koi and a mirror carp were crossbred. Asagi koi fish are light blue koi covered with dark blue scales and distinctive red markings. The mirror carp has lines of scales and slick, shiny skin.

A Shusui Koi with Orange and Black Markings
There are Armored Scales on the Back fo a Shusui Koi

When crossbred, these two Japanese koi fish produced the unique appearance and color pattern of the Shusui koi.

Shusui koi combine the very different looks of its two ancestor fish in an eye-catching way, giving it an appearance that sets it apart from other koi carp and making it a desirable addition to any koi pond.


The Shusui koi fish is most notable for the eye-catching contrast between its light blue base color, which is unusual for koi fish, and its bright red markings, which stand out in comparison. The red markings usually appear on the Shusui koi’s sides and fins. 

The Shusui also sports a dark blue or gray, reflective color on its scales and white or light blue on its head, sometimes with red markings on the cheeks.


Another unique aspect of the Shushui koi fish’s appearance is its scales. Unlike the Asagi from which it descended, the Shushui is not evenly covered in scales. Instead, it inherited a single row of scales from its Mirror Carp ancestor, while the dark blue coloring of the scales can be attributed to the Asagi.

This single set of scales runs along the dorsal fin and lateral line from a spot near the head all the way down the tail. 

A Single Shusui Koi with other Brightly Colored Koi
Shusui Koi is Mirror-scaled Unlike Most Koi


Added to the striking and unusual scale pattern on a Shusui koi are its vibrant, eye-catching red markings. These markings vary from fish to fish but are often found on the sides and fins. They are generally symmetrical in appearance.

The contrast of these gorgeous red markings against the light base color and dark scales makes the Shusui one of the most attention-grabbing fish in the pond.


The primary standards for the body of the Shushio koi have to do with the scales and the markings.

The scales should be evenly placed, with none missing and no gaps. They should be a uniform color and slightly reflective and should only be found on the dorsal fin and lateral line. The rest of the body should be Doitsu, which means unscaled.

A photo of a Single Shusui Koi Fish
Shusui Koi have Black markings on the Cheeks, Head, Body, and Fins

The markings on the body of a Shushui koi should be symmetrical. A spot of red on one side of the fish should be matched with a similarly sized and shaped mark on the other side. For example, if a red marking appears on one fin, it should also appear in a similar pattern on the opposite fin.

The head of a Shushui koi should generally be white or a very light blue. There should be no spots or discoloration on the Shushio koi’s head.

The cheeks of the Shushui koi are often adorned with large red spots, giving them a cheerful, whimsical look.

A photo of a Shusui Koi with Other Koi That Have Different Markings
Shusui Koi is a Doitsu Version of Asagi


The Shushui koi has many unique colors and patterns that set it apart from other varieties of koi fish. Bearing the combination of two of their ornate Japanese ancestors, any koi hobbyist would welcome this beautiful addition to their outdoor pond.

Thinking about adding Shusui Koi to your pond? You can find a vendor locally or online who can ship directly to your door. You can find a store that sells Shusui Koi Fish in our online providers directory.

Frank Salvatore

In 2015 our family moved into a house south of Denver, Colorado with a  koi pond.  Since that time I've learned to really enjoy the koi fish and the pond. This blog is dedicated to providing helpful hints and information for koi pond hobbyists - as well as those of you who just inherited a koi pond and are thinking NOW WHAT?

About Me

Hey there - I'm Frank Salvatore. In 2015 our family moved into a house south of Denver, Colorado that had a Koi pond. The problem was I knew absolutely NOTHING about koi ponds.

This blog is dedicated to providing helpful hints and information for koi pond hobbyists - as well as those of you who just inherited a koi pond and are thinking NOW WHAT?
Learn More About Me

Related Blog Posts

Koi Services - Local and Online

Check out our list of koi services providers near you - as well as online koi supply retailers
Read More

Koi Fish Types

Let's take a look at the varieties of koi that are cherished by collectors and backyard koi pond owners
Read More

Sick Koi Fish

Koi are susceptible to illnesses just like their human caregivers. Here's how to identify and treat a sick koi fish.
Read More