Rarest Koi Fish Types – A Guide for Collectors

For many hobbyists, koi fish are their lifelong passion. These colorful and graceful fish are often the focal point of a pond or aquarium for many people. However, some species can be particularly difficult to find due to being highly sought after by collectors worldwide.

In this blog post, we will explore some of the rarest koi fish types and what makes them so unique.

Utsori koi
Utsori Koi | Photo by Simon Mugridge on Flickr

The Rarest Type of Koi Fish

By far Ki Utsuri is the rarest type of koi fish in the world and it was almost gone extinct. They generally have a combination of yellow over lacquer black body and they are judged by the same criteria as Hi Utsuri and Shiro.

The Ki Utsuri koi fish is created by cross-breeding of Magoi or black koi and Ki Bekko koi. The word “Ki” means yellow in Japanese where “Utsuri” means transparent.

The Ki Utsuri comes in two types:

  • Gin Rin Ki Utsuri
  • Kin Ki Utsuri

Gin Rin Ki Utsuri

This type of Ki Utsuri has a standard black and yellow body.

Gin Rin Ki Utsori Koi
Gin Rin Ki Utsuri Koi | Photo by Grand Koi

The color yellow in this Ki Utsuri stays more vivid without a color-enhancing feed. When color-enhancing foods are given to them, orange spots can develop within the yellow patterning on the Ki Utsuri. Eventually, the color yellow will be pushed toward being more orange.

Kin Ki Utsuri

This is the metallic version of Ki Utsuri, a black-based koi with metallic yellow patterning. Sometimes the pattern of Kin Ki Utsuri is associated with a checkerboard pattern or simply a bumblebee look.

Kin Ki Utsori Koi
Kin Ki Utsuri Koi | Photo by Pond Trade Magazine

They tend to have a more flat charcoal black and sometimes it is seen that they develop small black specks within the yellow or orange patterning. This type of Ki Utsuri is uniquely beautiful and can easily attract people.

Care Guide for Ki Utsuri Koi

  • They need a moderate level of care and you don’t have to carry extreme pressure keeping them.
  • They are very peaceful and friendly. Ki Utsuri manages a well-behaved pond life.
  • Ki Utsuri koi fish are generally sized between 28 inches and 40 inches.
  • If you are keeping them in a pond, then the minimum pond size should be 500 gallons.
  • The water temperature for Ki Utsuri should be 55 to 79 degrees Fahrenheit. Temporary water conditions can range from 34 to 85 degrees Fahrenheit.
  • Ki Utsuri koi fish are omnivorous animals.
  • They were originated in Japan.
  • The most preferred place for them to live is in a pond. The bigger place is better for Ki Utsuri koi fish to live.

How to Get The Best Quality Ki Utsuri

  • The black color on Ki Utsuri’s skin should be as lacquer black as possible. They should have smooth edges where the combination of black and yellow meets. If you see small black dots where the color meets, then that Ki Utsuri variety has a flaw.
  • The foundation of a Ki Utsuri is the black color and a good quality Ki Utsuri should have solid dark black color patterning. The black color should well-balanced across the whole body of the Ki Utsuri and the face of the fish. The color black on the face of Ki Utsuri covering the eyes or the mouth, in a v-shaped patterning is a sign of high-quality Ki Utsuri.
  • Good quality Ki Utsuri koi fish have black colored pectoral fin base and the rest of the fin is red. the black base of the pectoral fin of a Ki Utsuri is called ‘motogura’ and the more defined the color is, the better. If you see your Ki Utsuri having pectoral fins base colored black or almost black, then it is in a good shape.
  • The color patterning of black and yellow on a Ki Utsuri’s body should be balanced or sometimes the emphasis on the color black as they are a black color based koi fish. You should check this before choosing a Ki Utsuri.

Other Rare Koi Fish Varieties

The rarity of koi fish depends on their availability. You can visit a local shop and see some of the common varieties of koi fish for sale, unlike the rare breeds. They are hard to find and costs more than usual. You’d be surprised to hear that the most expensive koi fish was worth $1.8 million.

Kin Showa

Kin Showa koi fish is the metallic version of the regular Showa with sharp edges between the color patterning. They are a result of cross-breeding between a regular Showa and a Platinum Ogon.

Kin Sowa Koi
Kin Sowa Koi | Photo by Kodamakoifarm

Kin Showa displays a body of white and orange/red color patterns over the top of black base color and sometimes they are being confused with snakes. The black base color is wrapped all the way around the body of a Kin Showa, not only the upper half of the body. A good quality Kin Showa will have a well-balanced color patterning on their body.


Midorigoi is a rare and unique koi fish breed and it is a result of cross-breeding between Ogon and Shusui. They are single-colored and non-metallic green koi.

Midorigoi Koi
Midorigoi Koi | Photo by Kloubeckoi

Generally, Midorigoi doesn’t have a fully scaled body but they got Doitsu scales along their spine. If you are looking for a good quality Midorigoi then you should look for blemish-free green color and symmetrical Doitsu scales.


Kikokuryu is also a rare breed and they are scaleless (Doitsu) koi. They display a white based on their body with a combination of black inside and back outside the single row of scales. They have black color on their head around the eyes and their nose.

Kikokuryu koi
Kikokuryu koi

Frequently Asked Questions

How much is a koi fish worth?

If you are looking for pond quality koi, they typically cost 10 to 100 dollars. The value depends on their quality, a better quality koi fish means better color characteristics, better health, stable bloodlines, etc. you should never compromise the quality while buying koi.

Are black koi rare?

Karasugoi is the only true black-colored koi Japanese breeders have produced for quite some time. Recently, they were largely unknown in the west. You can find this koi variety up for sale in many places.

Can Koi breed with goldfish?

Yes, koi and goldfish can reproduce together. If you put koi and goldfish in a pond, you’ll notice little hybrid fishes produced by them.

Why is koi fish so expensive?

Koi fish is well known around the world and sometimes can be very expensive. The main reason koi fish are expensive is the low supply and high demand. It is seen that out of a million eggs, only 60percent can hatch. Thus, they are expensive in the market.


Koi fish comes in a huge variety and is well known for its beautiful body color feature. As they have been around us for decades, some of the breeds have gone almost extinct and rare. I hope you’ll be able to acknowledge about rarest koi fish varieties from this article.

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