If you’re a koi enthusiast, you probably know just how many breeds of koi there are, and it can be overwhelming to choose which kind to add to your pond. Today, we’re focusing specifically on the Butterfly koi, sometimes known as the “water dragon.”

Butterfly koi have long flowing fins, much like butterfly or dragon wings, that make them distinct from standard fin koi. Butterfly koi have a relatively new history–rooted in the US–and we’re discussing how this breed came to be, how to take care of them, and what the major differences are between butterfly koi and standard fin koi.

Where do Butterfly Koi Come From?

While most koi breeds have origins in Japan and China, butterfly koi actually have roots that are a little less clear. It is believed that in 1977, the Crown Prince of Japan was visiting Indonesia and spotted a koi carp with long fins, and he suggested they cross-breed with traditional Japanese koi carp. This led to koi breeding in Indonesia and alas, the “Butterfly Koi” or “Hirenagagoi” koi was born in 1982 in Japan, but they have history in the US too.

The origins of butterfly koi in the US came around the same time that the Hirenagagoi in Japan were being bred. Koi specialists Randy LeFever and Rick Brown, pioneers of Blue Ridge Fish Hatchery in North Carolina, saw an opportunity for breeding what was then advertised as “long-finned koi” with their koi supply. And well, the rest is history. Due to their unique fins and clear differences from traditional koi carp, they were dubbed the Butterfly or Dragon Koi, and they have gained both popularity (and controversy) in the years to follow.

Want to know more? You can read the full story here.

Popularity and Controversy

Because this breed is so new, it’s not surprising that there’s a little bit of controversy around their popularity from koi enthusiasts. Some koi hobbyists believe that Butterfly Koi are superior due to their unique fins, coloring, and overall newness to the koi world. They are largely popular in Europe and Asia, and they have gained traction from breeders in the United States and most of North America due to their breeding origins in North Carolina, which makes them readily available for purchase. They are even sometimes known as “American Koi” for how much they are bred in the US, which is why so many of the world’s most prestigious breeders continue breeding and selling Butterfly Koi.

However, not everyone feels so warmly about these water dragons. Because they are the result of decades of inbreeding, some believe that they are an inferior breed of koi and aren’t as “natural” as Japanese koi. Some hobbyists don’t even consider Butterfly Koi real koi. Others erroneously believe they were crossbred with goldfish, resulting in their longer fins (they weren’t, to be clear). In fact, butterfly koi aren’t allowed at most koi shows and competitions, known as “Nishikigoi” judging, as some organizations refuse to recognize them as koi.

The standard criteria used in koi shows have evolved and changed over the years, but they continue to be specifically tailored to rate the characteristics of traditional standard fin koi, even though the butterfly koi now holds over 40 years of breeding and history. In fact, many breeders in the US and all over the world have worked tirelessly to try and develop butterfly-finned varieties of traditional koi patterns to qualify. These patterns include iconic ones, such as Kohaku, Sanke, Showa, and more.

Whichever way you feel, the butterfly koi are a beautifully special breed that certainly gets people talking.

Butterfly Koi Care

You’re probably now wondering if this new long-finned breed of koi needs its own special kind of care that differs from standard fin koi, which is understandable if you’re considering diversifying your pond.

Good news for those curious about butterfly koi: care and maintenance are pretty much exactly the same as their short-finned friends, just make sure to keep a close eye on their long fins to prevent any tearing or injuries. Butterfly koi have an average lifespan of about 25-35 years, though some believe they might live longer due to their close breeding with traditional water carp. As long as your pond is properly aerated, free of bacteria, and well-fed, you will have a happy ecosystem at your fingertips.

Interested in adding a butterfly koi to your pond? Shop our selection now!

5 responses

  1. I just started with the butterfly I keep them in a 55 gallon tank. They are thriving very well. There are 3 of which 2 are the butterfly. How long can I keep them in an aquarium setting.

    1. Hi Linda,

      The rule of thumb for keeping koi is 10 gallons of water for one inch of Koi. Koi can easily reach sizes of 20-24″ in length in optimal conditions. This should help to evaluate if you can safely keep these fish in your tank. We have provided some additional information in another blog article about Keeping Koi in an Aquarium via the link below:


  2. koi can be kept in an Aquarium, or I should say started in an aquarium. Most aquariums would be far to small for Koi beyond one or two years. This does not take into account filtration either, only size. Koi like Goldfish are a very dirty fish, so filtration with be paramount. I used two FX6’s to keep a 150g clean. I only had 3 but had to finally transfer to a 1500g outside due to size. The big issue with most is the lack of filtration a little filter will not keep a tank clean. Ammonia is another big issue with Koi. Most people shouldnt get Koi for the single reason of growth. They dont have the ability to keep upgrading the size of tank and filtration.

  3. John Linde :

    I’ve raised Koi for over 40 years They belong in a pond not an aquarium because they grow very big In a pond they need plenty of oxygenated water which requires a waterfall or fountain pump I have raised Champion Koi for many years but now just love the few I have in my pond

  4. My husband and I prefer long-fined (butterfly) koi.. we have 32 fish in our pond and only ( are standard fin. Many are gorgeous! Thanks for the wonderful article!!

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