Get to Know Koi Betta Fish - Tancho, Galaxy, Tiger, and Emerald

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By Linh Nguyen Updated on 12 May 2023

The Koi Betta fish is a beautiful and popular strain of the marble betta family. These gorgeous fish boast lavish colors like red, black, orange, and yellow that create an eye-catching pattern reminiscent of traditional Koi fish. With various types available, even experts may have trouble telling one species from another. Whether you are looking for a new pet or simply curious about this unique breed, learning more about these bettas can help you decide if they are right for you.

In this blog post, we will explore what makes a Koi Betta special and how to care for them properly. We will also discuss the different varieties available so that you can find the perfect addition to your aquatic home! So without further ado, let’s dive into the world of Koi Betta fish!

1. What is Koi betta fish?

A Koi Betta is a pale-based marble (cellophane) with red, black, orange, and yellow markings on the body, similar to that of a classic Koi.

They were originally bred for top-view. This seems to be a new direction for the betta hobby with the release of betta fish in rockeries and ornamental pots.

At the Holland Betta Show 2016, there is a special class of exhibit: Koi Bettas, to be judged by Koi Referees! The referees judge from both the top and side views.

A normal koi will show an even amount of red, black, white, orange, and yellow typically having more white amounted to red, orange, black, or yellow with the black, orange, yellow, or red overlapping at some points but not excessively. The top and sides should all be evenly patched. Judged by side and top down. Patterns on the top only or on the side only are marbles and will change a lot with age.

An award-winning Tiger koi at The Holland Betta Show 2016.

An award-winning Tiger koi at The Holland Betta Show 2016.

2. The special feature of Koi betta fish with other Marble fish lines

Marble and Koi are for sure not the same and Galaxy is not Koi either. Iridescent scales make the galaxy (trade name) because the breeders of the first galaxy marbles thought the scattered iridescent scales looked like a galaxy of stars in the night sky or so the story goes.

Genetically speaking, today most fancy marble probably carries marble genes and thus will go through color changes throughout the life of the fish. Since marbles are unpredictable, patterns may also change. and with USA and Europe standards so messed up and so many standards far apart and incorrect people think marble is koi.

Koi bettas or true Koi bettas will not change color or pattern after a cretin time in their life. This phenomenon in koi fish has not been satisfactorily explained. However, there are many theories that this is caused by a defective gene, which causes the color layers to not be repaired after some time.

With a true Koi betta, the color and the pattern will look almost the same at 1 year as they did at 3 months. Sure the color will fade a little or the pattern will not be as sharp but it will be very close to the 3-5 month pattern you saw when the fish was younger.

On a marble Koi (only looks like a koi for a time) the fish might not even look like a Koi when older and some turn to just patches of red shades.

Although with today’s standards, both at 6 months would be judged as Koi and the owner of the marble that looked like a Koi would have a new fish after a year or so that might not even look like a Koi.

One of the items overlooked when evaluating a true Koi betta is the quality of the base color of the fish. Today most judging on Koi bettas is a little flawed, fish that have lots of color and patterns are sometimes winners. But, fish with better coloration bases and sharper patterns on older fish are sometimes overlooked because older fish do not always have better fins and bodies when compared to 6-8-month-old fish.

3. Different variations of betta Koi

Koi betta fish has the following variations:

Below are the classifications and corresponding colors of the Koi betta fish classifications.

Note: The red in all of this could be replaced with orange and still be considered a koi betta

3.1. Normal betta Koi

This is a fish line with the basic, classic colors of Japanese Koi fish. These often include color combinations such as:

  • Red/Black (red base)
  • Red/Black (white base)
  • Red (white base)
  • Black (white base)

Note: If a Koi Betta has a red spot on its head like the Japanese flag, it will be called a Tancho Betta.

A Tancho betta fish with red on a white background resembles the Japanese flag.

A Tancho betta fish with red on a white background resembles the Japanese flag.

3.2. Galaxy Koi

When breeders add blue to a traditional koi betta, we get a Galaxy Koi Betta. This fish is characterized by iridescent scales on its body, resembling a glittering galaxy.

Some of the base colors include:

  • Red/Black/Blue (celo based)
  • Red/Black/Blue (white based)
  • Red/blue (white-based)
  • Red/Blue/black (celo based)

Note: What makes a Koi bettas a Galaxy is the showing of excessive blue coloration with the koi coloration and scattered iridescent scales.

A Koi Galaxy betta fish with red, black and blue colors.

A Koi Galaxy betta fish with red, black and blue colors.

3.3. Yellow Galaxy Koi

Once you replace the red color of the Galaxy Koi with yellow, the Yellow Galaxy Koi variant will be obtained. These include some basic color combinations such as:

  • Yellow/Blue (white based)
  • Yellow/Black/Blue (celo based)
  • Yellow/Black/Blue (white based)
  • Yellow/Blue (red-based)
A Yellow Galaxy Koi betta fish with yellow, blue color.

A Yellow Galaxy Koi betta fish with yellow, blue color.

3.4. Yellow Koi ( Tiger Koi)

Yellow Koi betta fish is also known as Tiger Koi. Here are some combinations of their colors:

  • Red/Yellow/Black (white based)
  • Red/Yellow/Black (celo based)
  • Red/Yellow (white based)
  • Yellow (white-based)
  • Yellow/Black (celo based)
  • Yellow/black (white based)

Note: What makes a Tiger koi (Europe) a Tiger is that it features an excessive amount of either yellow or red and features minimal white with black ‘stripes’ or Black splotches/spotting.

A Tiger Koi betta fish with distinctive yellow and black color.

A Tiger Koi betta fish with distinctive yellow and black color.

3.5. Emerald Koi

An Emerald Koi will include the following variations:

  • Red/Yellow/Black/Orange (white based)
  • Red/Yellow/Black/Orange (celo based)
  • Red/Yellow/Orange (white based)
  • Yellow/Orange/Black (white based)
  • Yellow/Black/Orange (celo based)
  • Yellow/black/Orange/Blue (celo based)

Note: New Emerald is now Yellow/Orange/Black/Blue and dragon scale) it is celo based for now!

An Emerald Koi betta fish.

An Emerald Koi betta fish.

3.6. Candy Koi, Copper Koi, Nemo Koi, and Tangerine Koi

In addition to the aforementioned names, we have also come across many different names such as Candy Koi, Copper Koi, Nemo Koi, and Tangerine Koi.

After many attempts to find pictures and videos on the internet, we have come to the conclusion that no new line of betta Koi fish has appeared. These seem to be trade names used by vendors to create novelty in the market. They are crosses of Koi bettas with their respective lines and, of course, do not really have a definition, color palette, or specific classification.

A Candy Koi betta fish.

A Candy Koi betta fish.

A Nemo Koi betta fish.

A Nemo Koi betta fish.

4. Overview of Koi Betta Fish

4.1. Size

The term "Koi" is used to refer to the pattern and coloration of the betta fish. Therefore, this does not affect the size of the fish. The size of a Koi betta depends on its breed; thus, there are many different sizes for this line of fish. If it is a Plakat, it will only be 2 to 3 cm in size. If it belongs to other lines, it will be larger, ranging from 4 to 6 cm. Should your betta be a Giant, it will measure over 7 cm in size.

4.2. Lifespan

The lifespan of bettas is generally not affected by their coloration; therefore, like their relatives, a Koi betta will have an average lifespan of 2 to 3 years and of 5 years in favorable captivity.

4.3. The behavior

Koi betta fish are an aggressive species of fish, making them unsuitable for a tank with other fish. When placed in the same school as other fishes, they tend to become easily agitated. They prefer environments where they can have space to themselves and be comfortable without interruption. Additionally, they are quite active swimmers and enjoy exploring their surroundings through swimming and leaping out of the water at times.

4.4. Prices

Koi bettas are a popular breed of fish and can be quite expensive to buy. Generally, Koi Bettas sell for around $15-20 USD each, but prices may vary depending on the type of betta you are looking for. This is more expensive than other types of Betta fish like Crowntail Bettas which sell for about half the price or less.

When considering where to buy your Koi Betta from, it's important to find a reputable breeder who will provide healthy fish with good genetic lineage. Reputable places to purchase Koi Bettas include online stores such as Aquabid and eBay, local aquarium shops, or dedicated fish forums such as Monsterfishkeepers.

A Galaxy Koi betta fish.

A Galaxy Koi betta fish.

5. Care

5.1. Choose varieties

To have healthy fish, the selection of the breed is very important; therefore, you should pay attention to the following:

Choose fish with a balanced body structure, which is reflected in the appropriate proportions of the head and base of the tail. In addition, the body parts of the fish should not be too big or too small; these are the healthiest and best-growing fish.

You should go to large aquarium stores to choose the most suitable fish. In a large school of fish, pay attention to choosing fish whose head length is 1/3 of the body length. This is the body proportion that helps the fish move more easily.

Koi fish are an aggressive species, and this is also a criterion to help choose the best breed. Aggressive fish tend to be healthier and reproduce better. For female fish, choose those with round bellies; if they have a white anal part, it means they are ready to breed.

5.2. Tank setup

Koi Betta does not require too much in terms of habitat. The size of this aquarium does not need to be too big; just a tank with a size of 12 x 17 x 20 cm is sufficient for the fish to live comfortably. The aquarium also does not need aeration equipment, as the fish have accessory respiratory organs. You can add seaweed and algae to increase aesthetics.

However, there is one requirement that aquarists should remember: they should not be placed in a place with direct light. The ideal water temperature is 24 - 30 degrees Celsius, the water hardness is 5 - 20, and the pH is 6 - 8.

5.3. Food and nutrition

Food is also an essential part of the development of betta Koi fish. However, if you are raising these fish for the first time, you can be at ease since this is an omnivorous fish. They will devour nearly anything you put in the tank. Therefore, just find out what foods they relish and you can bring them up in a healthy manner.

Bettas and Koi fish are very fond of eating foods such as larvae, worms, insect larvae, etc. However, these foods should be purchased from reputable fish stores to ensure quality. Additionally, after buying them, they should be thoroughly washed before feeding them to the fish.

Feed the fish twice a day, in the morning and afternoon, and give each time a number of worms equal to that of green peas. The amount of food should not be too much or too little so as to affect the growth of the fish.

5.4. Maintenance mode

Raise a healthy fish, it is not only about creating the right aquarium and feeding a balanced diet. You should also pay attention to the following:

These are the main fighting fish, so it is best to choose a small tank and keep each individual separately Tanks placed next to each other need to be well covered, as just seeing the opponent can trigger an attack reflex in these fish.

However, aggression is in their nature, so it is advisable to let them encounter each other from time to time; this will make them stronger and more flexible.

It is necessary to ensure that the fish culture environment is clean and free from harmful bacteria for the fish. Therefore, aquarists have to change the water regularly, usually once a week.

A Yellow Galaxy Koi betta fish.

A Yellow Galaxy Koi betta fish.

6. Diseases

In the process of raising fish, it is very important to learn about common diseases and how to treat them. Here are some common diseases in koi betta fish.

6.1. White spot disease

When you see beneath the skin of Koi betta fish, white spots caused by parasites residing like salt particles cover the fish's body. The fish may try to swipe itself against objects in the tank. The disease is easy to spot and treat. In this case, you need to increase the water temperature to limit the growth of parasites. Bathing the fish in salt water or using a healing solution for a few days will cure the disease.

Read more: Ich On Betta Fish: What It Is, Symptoms, And Treatment

6.2. Gill disease

When suffering from this disease, Betta fish will still eat normally for the first time. But then they eat less, float to the surface and die. The scales on the fish's body will be ruffled, when peeled off, it can cause bleeding. You need to instill RID PROTOZOAN with a dosage of 2 drops/2 liters of water. Combine soaking Japanese tetra to increase the effectiveness of disease treatment for fish.

Read more: Bacterial Gill Disease In Bettas: Causes, Symptoms, And Treatment

6.3. Fin rot and tail rot

This disease is caused by poor water conditions in the tank, which allows bacteria to grow rapidly. From a minor injury, the fish can develop fin rot; the fin rays become frayed, and red blood stains appear. When fish are ill, we place them in isolation tanks, treat them with antibiotics and clean their wounds using mildly acidic water.

Read more: Betta Fish Fin Rot: What Is It, How To Treat, And Prevention Tips

7. Breeding

The techniques for breeding a Koi betta are similar to those of other regular bettas. Here are some experiences I would like to share:

  • Breeding a marble to a marble gives you marbles 100%.
  • Breeding a koi to a marble gives you marbles 100%.
  • But breeding a koi to a koi will give 90% koi on F1. 10% will have a marble gene that will not turn off or will turn off slowly leaving a marble in the end.

The koi’s will not change much after 8 months to 1 year and what you see is what you get. Judging a young marble as a koi is just a lack of knowledge. The minimum age for judging a koi should be 1 year as it will weed out the marbles. Lots of young marbles look like koi only to become ugly reds or washed-out blues when older.


So, while it may be challenging to take the plunge and get into owning a Koi Betta fish, with a bit of research and patience you can create an environment in your tank that works for both your fish and yourself. With the colors, sizes, and pattern options available, there is sure to be one perfect for you. If you haven't already taken the time to bring this gorgeous fish into your home, make sure you do! And if you have, please let me know in the comment below what else I should consider when thinking of getting my own Koi Betta Fish. Investing the time and effort into understanding what makes them thrive can be very rewarding — both for your betta fish and yourself. As always, enjoy watching them grow and live their lives in your own tank!


1. I just purchased a Tangerine Koi Betta from the store the other day. I was wondering is he really is called a Tangerine Koi or if he is some other type of koi betta.

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