Butterfly Koi: The Ultimate Guide to This Popular Koi Fish Variety

If you are a koi fish hobbyist looking to add a wide variety of koi fish to your backyard pond, butterfly koi can't be left out. While some koi fish enthusiasts think of butterfly koi as a "mutt" variety, and some say they shouldn't even be classified as koi, others consider this variety the finest in any collection.

Butterfly koi are known for their stunning beauty, gracefully gliding through ponds with a beautiful shadow of long fins trailing behind them. It can't be denied that the unique aesthetic of the butterfly koi makes them the perfect choice for koi fish owners looking to add something a bit different to their ponds.

As one of the most popular koi fish varieties in our inventory, we have a special place in our hearts for the butterfly koi here at Koi Fish USA. Today, we will be offering a complete guide of everything you need to know about butterfly koi.

If you're interested in adding one (or several) to your collection, you'll need the information provided in this article. Not only will we be explaining what a butterfly koi is, but we will also discuss their history, provide care instructions, and offer some helpful tips on how to select the perfect butterfly koi for your collection. Let's get started!

What is a Butterfly Koi?

According to strict Japanese definitions of "koi," butterfly koi fish are not technically koi. Instead, butterfly koi are a cross between a long-finned Indonesian carp and traditional koi (part of the carp family). However, for those that don't consider themselves strict collectors, a butterfly koi is a koi fish in all of the ways that truly count: behavior, coloring, diet, longevity, and general appearance.

In reality, the primary way that butterfly koi vary from standard koi is found in their fins. Unlike traditional koi fish, butterfly koi don't possess the genes that tell their fins to stop growing at a certain point. For this reason, their fins grow longer and longer throughout their lifetimes. This results in long, flowing fins that are undeniably beautiful. This is where butterfly koi got their name as their fins resemble the grace of a butterfly's wings.

Another apparent difference between butterfly koi and standard koi is the body itself. Butterfly koi have bodies that tend to be slightly more slender and narrow than traditional koi. Additionally, their barbels (the whiskery growths extending from their faces) grow somewhat longer than a traditional koi.

Are There Different Varieties of Butterfly Koi?

Similar to standard koi fish, there are different varieties of butterfly koi. Many koi fish breeders can selectively breed the butterfly fins into nearly every type of koi fish. Some varieties are rarer than others, but they all possess the unique beauty of the butterfly koi's long fins. This section will provide a short description of a few of the most popular varieties of butterfly koi (which can also be found in the standard koi).


The Showa butterfly koi is a member of the Gosanke family of koi. In the Showa variety of butterfly koi, the body is primarily black with white areas and red patterning overlaying the black. The standard Showa koi was first produced around 1927 and is the product of cross-breeding a Ki Utsuri with a Kohaku koi.


The Sanke butterfly koi, also referred to as the Taisho Sanshoku, is also a member of the Goasanke family of koi. They are known for their solid white bodies and areas of both red and black overlaying the white. Today, most Sanke koi fish in the koi fish industry are thought to be traced back to the Torazo bloodline. 


The Kohaku butterfly koi is a solid white koi fish with red patterns overlaying the white. It is believed that Kohaku is one of the first varieties of koi fish ever developed, and they remain one of the most popular varieties to this day. This variety first appeared in Japan between 1804 and 1829, when a black carp with red cheeks was discovered.


The Utsurimono butterfly koi possess three different color varieties: red, yellow, and white. This variety of koi is known for being one of the most beautiful. This is represented in its name, which translates to "reflections" or "reflecting ones."


The Asagi butterfly koi is blue with a net-like reticulated pattern extending across the back. This pattern is accentuated by areas of red found on the gill plates, belly, tail, pectoral fins, and sometimes around the dorsal fin. This variety is among the oldest types of koi fish.


The Shusui butterfly koi fish is a German koi where blue scaleless skin replaces the netted pattern of the Asagi koi fish. They possess a single row of scales running down the dorsal line. The Shusui is also known for red spots, which can extend above the lateral line and onto the fish's back.

Yamabuki Ogon

The Yamabuki Ogon butterfly koi is the most popular and readily available Butterfly Koi.  It's bright yellow coloring and metallic coloration make it a staple for almost every koi pond.

The History of the Butterfly Koi

Now that you know a bit more about what butterfly koi are and a few of their different varieties, it's time to discuss the history of the butterfly koi. Surrounding the origin of the butterfly koi, we know that they started as a breed of long-finned carp. Breeders only started selling butterfly koi commercially in the mid 20th century. Beyond these basic facts, the exact history of the butterfly koi is up to some debate.

Some sources report that Japanese breeders began cultivating long-finned koi long before the fish made its way to the United States. Others say that the breed came into popularity as late as the 1980s when breeders from the North Carolina-based Blue Ridge Fish Hatchery bred long-finned feral carp that they got from New York.

Still, a famous story surrounding the origin of butterfly koi dates back to July of 1977. This year, Crown Prince Akihito, who visited the Saitama Prefectural Fisheries Experiment Station, suggested that a carp existed with a long fin in Indonesia. He went on to suggest that this variety be crossed with the Japanese pond smelt. This prompted the Saitama Prefectural Fisheries Experiment Station to start breeding long-finned koi in 1980. According to these reports, the first butterfly koi was born in 1982.

Although butterfly koi are also sometimes referred to as "dragon koi," they were first coined "butterfly koi" by Randy LeFever, the son of Wyatt LeFever, a noted koi breeder, who first suggested that their long fins resembled that of butterfly wings. The name stuck, and we have referred to long-finned carp as "butterfly koi" ever since.

Caring for Butterfly Koi Fish

Suppose you are an experienced koi fish owner. In that case, you likely already know that caring for a butterfly koi fish possesses few differences from that of a standard koi fish. Specifically, you can feed your butterfly koi just as you would a traditional koi. Additionally, just as caring for standard koi fish goes, you should be sure that you keep your water aerated and that your butterfly koi have plenty of shelter from the sun and possible predators. Best of all, due to their docile nature that is identical to other varieties of koi, butterfly koi can live happily alongside goldfish, catfish, and different koi varieties.

Basic Care Instructions for Butterfly Koi

There are a series of steps that you can follow to care for your new butterfly koi. While these instructions are almost identical to the primary care instructions for a standard koi, we felt it might be helpful to offer a refresher, breaking down the process step-by-step. For more detailed instructions on how to care for a standard koi, check out our "Ultimate Guide for Caring for Your Koi Fish." With that, here's how you should go about caring for your butterfly koi.

Step 1

Your butterfly koi should be put into a pond that holds at least 1,000 gallons of water. The pond should also be more than a meter in depth. While small butterfly koi can be kept in a large aquarium, this is not their preferred environment. Remember, all koi fish ranging from butterfly koi to standard koi, require ample space to swim freely.

Step 2

It would be best if you took care to add some sturdy-rooted plants to your pond. This is because koi fish tend to nibble on plant roots. Encircle your plants with stones to help minimize the damage that occurs during this process. Some of the most highly recommended plants for a koi pond include water hyacinth, water smartweed, water lotus, water lily, scouring rush, water lettuce, and eelgrass.

Step 3

Maintaining your koi pond's water quality will be essential to the happiness and longevity of your butterfly koi. Keep the pH of your pond at a neutral 6.8 to 7.2 range for the best results. If you're using a concrete pond, you should remember that the materials used in the concrete will cause your pond's pH levels to rise naturally. To reduce this effect, we highly recommend using a top coating on the concrete.

Step 4

In terms of feeding your butterfly koi, you should take care to only provide your koi high-quality pellet food with no more than 30 percent of protein. Bear in mind that the occasional shrimp treat is also acceptable. Still, pellet food is essential to a balanced diet for butterfly koi. In terms of frequency, your butterfly koi should be fed no more than two times per day during warmer months and less during the colder winter months.

Overfeeding koi fish is a mistake that many amateurs make and should be carefully avoided. This is because overfeeding your butterfly koi will change the balance of the pond over time. If your butterfly koi cannot eat the food you supply them with quickly, you are overfeeding them.

Step 5

You should consider adding a heater to your butterfly koi pond. Butterfly koi are cold-water fish, but too much cold can be deadly to them. Koi fish can handle temperatures between 33 and 90 degrees Fahrenheit. If temperatures in your area ever fall below 33 degrees, a heater can keep your butterfly koi from freezing to death. This is a crucial step in caring for your butterfly koi.

Step 6

You'll also want to do your part to protect your butterfly koi from potential predators. One of the best ways of doing this is to install a string net above the surface of the koi pond. This will safeguard your fish from predators- something that needs to be taken seriously. It's important to remember that the bright colors found on the body of a butterfly koi can easily attract unwanted attention for animals looking for a snack.

Step 7

You should take the need not to overstock your koi pond very seriously. Koi fish tend to panic and fight over both oxygen and food when they're feeling overcrowded. Additionally, the more room that your butterfly koi feel they have to swim freely, the better. It's always best to add fewer butterfly koi to your pond than too many, so select your koi fish with this in mind.

In general, there are three main rules you should follow when deciding how many koi fish is appropriate for your pond. The first rule states that there should be 6 inches of fish for every hundred gallons of water. The second rule says there should be 1 inch of fish for every ten gallons of water (for well-filtered and aerated ponds). Third, there should be 1 inch of fish for every square foot of surface area (for a 2-foot depth pond).

You'll want to keep in mind the length to which your butterfly koi have the potential to grow when using each of these rules. That brings us to our next section- one of the most frequently asked questions about butterfly koi: how big do butterfly koi get? For now, use the following as a basic guideline for deciding how many koi fish your pond is capable of supporting:

  • 100-gallons: 1 smaller fish
  • 150-gallons: 1-2 smaller fish
  • 250-gallons: 1-2 koi
  • 300-gallons: 1-2 koi
  • 500-gallons: 2-4 koi
  • 750-gallons: 3-5 koi
  • 1500-gallons: 6-10 koi

How Big Do Butterfly Koi Get?

While butterfly koi are slimmer than their short-finned relatives, they usually grow to roughly the same length as standard koi. At their longest, most butterfly koi grow to approximately 12 to 15 inches. That being said, some Japanese koi are known for growing even longer. Specifically, some jumbo varieties have been known to grow as much as even 3 feet long, although this is a bit rarer.


So how long can you expect your butterfly koi fish to live? Again, similarly to standard koi, butterfly koi are typically expected to live between 25 and 30 years in the ideal conditions. Still, some koi owners report that butterfly koi are slightly hardier than short-finned koi and may live even longer. This is likely because their hybrid genes and close ties to wild carp give them a heartier nature.

Are There Differences Between Caring For a Butterfly Koi and Standard Koi?

So, are there any fundamental differences between caring for a butterfly koi and standard koi? After all, those looking to raise their butterfly koi to be happy and healthy successfully will need to be aware of any potential differences in care instructions. Put simply, there isn't much of a difference between caring for a butterfly koi and caring for a standard koi fish.

The only precaution that you should keep in mind, in reality, is that you should try to show extra caution with your butterfly koi due to the fragility of their long fins. This is because their long fins are known for tearing and bending easily. Any sort of damage to these fins, although purely cosmetic, will be permanent.

Are Butterfly Koi Fish Aggressive?

One of the most common questions we receive here at Koi Fish USA is whether or not butterfly koi fish are more aggressive than standard koi fish. The short answer is that butterfly koi are no more aggressive than standard koi fish. That being said, there can be times where a koi fish of any variety can be aggressive, going so far as even to bully other fish in the pond.

A few different factors may account for aggressive behavior among your butterfly koi (or standard koi). This section will offer some insight into what may be causing your butterfly koi to act up.

1) General Temperament

Personality can be a heavy factor in whether or not your butterfly koi are aggressive. Suppose you notice that your butterfly koi seems naturally aggressive for no apparent reason. In that case, it is quite possible that you simply have a more aggressive koi. Fish with more aggressive personalities may chase other fish around the pond, fight for food, or do their best to be the first to the surface of the pond when food is being offered.

2) Lack of Space and Overstocking

As noted above, it is essential that you not overstock your koi pond and leave ample space for your butterfly koi to swim freely. While this is crucial in terms of health, it can also be necessary due to the ability of lack of space and overstocking to incite more aggressive behavior in your koi fish. If there isn't enough space in your pond, your fish will likely start to exhibit aggressive behavior as they battle for food, space, and shelter. Never overstock your pond if you want your koi to be happy and healthy!

3) Breeding and Spawning

During spawning, male koi fish can become hostile towards other males as they compete to fertilize females' eggs. Behavior that is commonplace between males during these periods includes nipping and shoving. Some injuries may occur to both males and females during periods of spawning, so ensure that your water quality is excellent to aid your butterfly koi in the healing process!

4) Poor Quality Food

Similarly to space, not having enough food is a common reason for your butterfly koi to act more aggressively to obtain the nutrition they desperately need. Aside from feeding your koi enough, ensure that you are providing them the right types of food to ensure that their diet is balanced correctly.

5) Injury or Illness

When a koi fish is sick or otherwise injured, it can become highly irritable. While this depends on the particular fish itself, some koi may lash out due to an instinctual drive to keep themselves from being the "weakest link" when they are sick or injured. Injured or ill koi fish may become restless, sluggish, hostile, or even seem depressed until their health is restored.

6) Poor Water Quality

Again, water quality should be a priority for you as you care for your butterfly koi. Not only does the quality of your pond's water impact the health of your butterfly koi, but it can also affect their behavior. Poor water quality can result in your koi fish becoming sick, stressed, or cause them to act otherwise "off." Keep this in mind if you notice any of your butterfly koi acting strangely.

7) High Stress Levels

Finally, much like humans, koi fish are much more likely to act out when they're under extreme stress. Not only does stress make your koi fish more susceptible to disease, but it can also make them act more aggressively toward each other. Keep your koi fish as stress-free as possible by caring for them appropriately!

How to Choose a Butterfly Koi For Your Collection

If specific guidelines are held in careful consideration when choosing a butterfly koi for your collection, you'll ultimately end up with a more graceful and striking-looking fish. Most buyers don't know what to look for when adding a butterfly koi to their collection. This section will touch upon some of the guidelines that you can use to choose a butterfly koi that will make a beautiful addition to your collection.

When shopping for the perfect butterfly koi, you should first keep in mind that the relationship between the pectoral (side) fins to both the head and the dorsal (top) fin is very important. Secondly, when judging a potential butterfly koi, you should remember that the leading spine's strength on the pectoral, dorsal, and tail fin is equally crucial. This support keeps the fins supported better overall and creates that graceful gliding butterfly look that the variety is known for.

This same support holds the fin's rays together and helps them to be more resilient to damage. Without this support, the fins will eventually weaken and turn into useless filaments. This is a problem to be especially wary of in older fish. You should consider optimal long-term support when judging a butterfly koi.

Additionally, take into consideration that pectoral fins that resemble ribbons are commonplace. For a winner, you'll want to select a butterfly koi with pectoral fins resembling a Geisha girl's fan. On the other hand, loose and flimsy pectoral fins should be avoided, especially when you consider that these will only become more unattractive over time. If you follow these guidelines when selecting a butterfly koi, you will find a winning specimen much more quickly!

How Much Do Butterfly Koi Fish Cost?

When answering the question, "how much do butterfly koi fish cost" it's crucial to keep in mind that butterfly koi of good quality is more challenging to produce and, in turn, commands higher prices. Larger butterfly koi with perfect finnage, for example, are extremely rare and fetch the highest prices. You should always take the guidelines in the previous section into account when selecting a koi fish. Similarly, these guidelines can be used to determine whether or not you're getting a good deal in terms of price.

Here at Koi Fish USA, we price our butterfly koi depending several factors including, the size, quality and rarity of the variety.  In general our prices start at $40 and go up to $200.  Some of our larger, super high quality or more rare specimens may be priced up to $1000 or more.

Find the Butterfly Koi of Your Dreams At Koi Fish USA!

Now that you know the answers to some of the most frequently asked questions about butterfly koi, it's time to find the right supplier for your pond! Here at Koi Fish USA, we pride ourselves on supplying koi fish owners with the butterfly koi of their dreams. Our butterfly koi are disease-free, healthy, and high-quality. No matter the butterfly koi breed you have in mind, we offer just what you're looking for at reasonable prices.

With over 20 years in the online koi fish industry, we consider ourselves experts at what we do. Not only will we deliver your koi fish the next day, but we'll also be on call to answer any of your questions! Offering the best butterfly koi for sale, Koi Fish USA is your one-stop-shop for the best fish for your pond. Best of all, we offer a 14-day guarantee that covers all fish that we sell for up to 14 days after the arrival of your shipment. Contact us today with any questions, and be sure to browse our selection of butterfly koi for sale today!