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Koi Betta Fish | Are They Betta Or Koi Fish |

What is a koi betta fish? Simply Koi betta fish is the commercial name or the nickname for a fighter fish with a specific color pattern. They are known as Siamese Fighting Fish (Betta Splendens) as well.

People at once glance for their beautiful fins, and they do have a beautiful color combination throughout everywhere in their body.

The scientific name of Koi bettas fish is Betta Splendens. We can categorize koi betta to the family betta. They have originated from the marble betta, so with slightly different DNA and genes. The color combination of koi betta fish is unique and changing rapidly, with increase pigment intensity.

Koi betta

koi betta fish belongs to the gourami family as well, and their roots are coming from Thailand. This species has selectively bred, and you won’t be able to see the same everywhere around the world as aquarium fish. Still, naturally, they live in and originate from stagnant rice paddies and swamps in Southeast Asia.

They use the labyrinth organ for breathing. This fish care guide will help you to properly take care of koi betta fish.

Are Koi Betta Aggressive?

For this, we can simply say, “Yes.” Well, mainly the male koi betta fish is more aggressive towards another male betta, and they will end up in their fights by killing each other in the end.

The funniest thing is these males bettas aggressive for their own reflection sometimes. You should not keep two male betta in the same tank.

And there are periods that male betta is aggressive towards female koi betta fish as well.

When female betta try to get closer to the bubble nest, you can obviously see how male betta fish will change their nature.

And finally, these male betta are aggressive for certain tank mates as well. galaxy koi betta needs adequate hiding space in the fish tank.

are koi betta aggressive

How Fast koi Betta Grow? / How big do koi betta get?

These koi betta fish species are fully growing when they become older and approximately when they are around six or seven months. these fish also need good care to grow

But like mentioned, these situations vary with the caring and with the environment as well.

After eleven or twelve months, betta is approximately 2 to 2.5 inches long, and they are fully grown.

With the right condition, bettas, fish can grow up to 3 inches as well. The largeness of these species totally depends on their age and the care that you give to them.

Koi Betta fish lifespan

Well, with reasonable care and a good environment, straight away, lifespan can be two to three years. But keep in mind this is so variable with so many other factors too.

It would help if you kept in mind that when you buy a betta fish from a pet store, it’s already 6 or 7 months old, and you have left only two or two and half years with the betta fish.

Koi Betta fish lifespan

Koi bettas fish Care

When you see betta bowls or vases, you must be thinking about how pretty and nice they are.

But do you know those betta bowls, Vases, and tiny aquariums are killing betta? But still, people buy those stuff on a large scale.

So, using these kinds of aquariums won’t healthily keep your koi betta fish. You must find a larger space for betta at least five gallons heated tank, and water quality must be maintained regularly with adequate filtration.

When you select a tank, to keep in mind, you should choose one with a lid because betta is jumper.

koi betta care

Koi betta fish care requirements

Most people think Koi betta can live in every kind of water since they are originated from paddy fields of Thailand. But the truth is no.

For betta also, they need good care, and water should also be high quality and soft with a neutral to slightly acidic.

The water temperature should be 22C to 26C constantly, and you should check the temperature once a week at least.

To maintain the water quality and cleanliness, you can change and clean water twice a month minimum.

The tank should be quite big, and it should contain a minimum of 5 gallons of pure water. Even though the pet store sells you the fish with 1 gallon of water, don’t think they can live within a gallon.

Imagine if the koi betta fish lives in a natural environment, they can swim miles here and there. So they need space and a good environment. Refer below to get a rough idea to maintain the water quality of the tank

  • Water Temperature 22-26 °C
  • Ammonia/ammonium (NH3/NH4): 0
  • Nitrite (NO2): 0
  • Nitrate (NO3): <10
  • pH: 6.5-7.5 (a little more or less is no big deal, but < 8 is best).
  • General hardness (in dH): Rarely a concern unless your tap water is extremely hard. Anything between 3-15 dH (or even a little more) should be fine.
  • Carbonate hardness (in °KH): Also, rarely a concern unless you’re using water that contains 0 °KH, like pure osmosis water (which you should not be doing!).

Fish Tank size for koi bettas

Like mentioned earlier, small tank bowls are not good at all for betta fish even though they are pretty.

If you are going to put the betta with several tank mates, keep in your mind, the tank should be spacious, or you can take the minimum tank size of 20CM to 50CM tanks as well. or 10 gallon tank size

Well, to maintain a good environment inside the tank, you can follow a few steps.

Use some natural plants like Ana Charis, Java fern, or Java moss to provide oxygen inside the tank. And betta feels they live in a naturistic environment, and you can see the fish’s true behaviors as well.

You must use a filter and a heater to maintain a good vibe inside the tank. Even with the filter, you have to change the water regularly as well.

Betta mostly likes to spend their time on the water surface, and it is better to take tank

mates who live bottom of the tank. Amano shrimp, Snails, Kuhli loaches, Corydoras catfish, and Otocinclus catfish are friendly and less trouble tank mates for a betta in a tank.

Koi betta fish feeding

How much to feed a koi bettas?

Betta splendens (betta fish) are carnivorous, and since they are carnivorous, they need protein-based food.

koi betta fish lived in a natural environment used to eat mosquitos, frozen foods, brine shrimp insects or whatever float on the water surface.

However, usually, betta can stay without any food for two weeks. But it would help if you fed your betta as usual to maintain a good and healthy life cycle.

These fish need good NUTRITION if you want optimal betta fish care. When you go through the supermarket or the pet shop, you can easily find the betta’s exact food.

But when it comes to some flakes when they soak in the water, and those flakes go down and stuck in the bottom, betta will not eat food stuck in the bottom of the tank.

There is no exact amount that koi betta fish have as their meals, but for a grown betta, you can give two meals per day, and for a growing one, you can feed them thrice a day maximum.

But there is a tip that you can consider when it comes to providing to a betta; you can see a round shape in their belly when they are full of food.

But you must be careful with overfeeding because the belly area’s skin is stretching and when they eat more food, it is stretching more and more.

Naturally, female betta fish’s belly is any way round as well. When you find food for your betta, freeze-dried food, live food, and frozen food also can be given.

You have to concern about the more protein food when you find food for them as well.

How koi betta fish sleep?

World’s most scientists believe that fish also get some rest or sleep like humans and other animals as well.

When it comes to betta, they also sleep like others, but it is different. Betta fish are light sleepers.

There are a few reasons for that too. When they sleep tight, they think they are not safe from other fish, and betta who used to live in paddy or a natural water stream could have been attacked by another fish or the same breed of birds.

Therefore even with a small sound or a movement, they wake up so easily. Betta is active in the daytime, and they also prefer to have a rest at night.

When fish sleep, their color is fading away, and it is applicable for betta as well.

When they are fully awake, you can see the bright, rich color over their skin and fins; when betta sleep, they breathe too.

If you get a closer look at the fish, you can see it draw water from its mouths out through the gills, and they use less oxygen when they sleep.

If you see betta is floating vertically, don’t worry, it is having a good nap.

Koi betta colours and types

Do you know that the koi betta fish name has been created because of the patterns of their body? When we consider the colors and types of betta, there are few colors you can see.

The most popular and the typical color of the betta fish is steel blue, Royal blue and the bright blue. And refer below to get to know about the bettas’ colors and types in general.

What is marble betta?

Marble betta is one of the exciting types of betta fish. It is the name used to identify betta fish with a marble color pattern in the body. The most interesting feature about them is they change color during their lifetime.

This unique phenomenon is caused by a special gene called “Transposons or Jumping gene”. Fish have patches in their body and fins which contain unique pigments, which causes color variation.

These color pigments are not unique to marble betta, but fish may fish (but every fish d not change color as marble betta). The color variation in marble betta is not as sudden as octopus or squid. It seems to be a gradual process.

In the native environment, when they are first found, they are black and white in color. But after so many experimental breedings, now there are marble fish with every shade of color imaginable.

What is the jumping gene?

Transpose of the jumping gene was a recent discovery by a group of scientists. They observe this special type of gene (or DNA sequence) change its position within the genome (as name jumping).

There are pros and cons of these jumping genes. Their importance in the evolutionary process is definitely an advantage. But sometimes, these jumping genes can mask the function of another gene, which can cause a negative impact on an animal.

How Jumping gene affect marble betta?

As the name implies, this gene can change its location, unlike other genes. This can happen in several ways. As explained earlier, the jumping gene can mask a gene expression by jumping into its position.

For example, the red color of a fish is the result of a specific gene. If the jumping gene changes its location to red color gen’s position, its expression masked, and the red color of the fish can be disappeared.

This is happening in marble fish. Jumping genes mask the expression of color, displaying genes and cause it to lose color. But the jumping gene does not stay in one place for a long time. When the jumping gene decides to move into another place, the masking stops, and colors start to appear again in the fish.

Marble betta vs koi betta

Marble betta is a type of koi bettas. They have the same type of patchy appearance in their body. But every koi betta can not change their color. This color-changing ability of marble betta can be notorious for some aquarists.

But there may marble betta enthusiasts who enjoy the disappearance and coming back of the color.

Do Koi Bettas change color?

Yes, they change color. Bit color change with their age is slow. Sometimes fast color change can occure due to health problems or changes in water quality. They do not change color as Marble betta because Marble betta is a type of koi bettas but all marble bettas are not koi bettas.

transparent koi beta

The basic color pattern of koi betta fish

When considering the color patterns of koi betta fish there are 6 types. Marble, Fancy, Galaxy, Candy, Tiger, Nemo, Samurai

marble betta
Marble betta
Fancy koi betta
Fancy koi betta

Marble with 3 or more colors.

galaxy koi beta
galaxy koi betta

Marble with partial iridescent scaling.

Candy koi beta
Candy koi beta

Marble with black, red, & blue or yellow.

Tiger koi betta
Tiger koi betta fish

Yellow bodied fish with black or blue marbling.

Koi Nemo Plakat Betta
Koi Nemo Plakat betta fish

Marble with orange, red, and black.

Samurai koi beta
Samurai koi betta fish

Marble with partial dragon scaling.

Red Koi Cooper
Red Koi Cooper

Koi Betta Breeding

You have to keep in mind that you have to consider four categories when you breed koi bettas mutation, colors, and patterns of the fish.

So, with these elements, you can have different and various kinds of betta fish as well. You can simply know when your female betta is ready to receptive, her color will get darken, and she will display her barring pattern as well.

Female koi betta fish lay eggs, and they can lay around 10 to 40 eggs at once. The male betta will make the bubble nest to keep the eggs before the female betta lay the eggs.

When female betta fish are done with laying, male betta will take care of the eggs, and it will take three days to hatch those tiny eggs, and baby betta will come out. They are called “fry” when they are freshly born.

koi beta breeding


Can betta and koi fish live together?

Well, the answer is simply no. Koi is a big fish than a koi betta, so if they live together in the same tank, most probably koi fish will end up eating the betta fish.

You can have a few koi betta fish in a tank, but three or four female koi betta fish with one male oi betta is an ideal combination because always two male koi betta are going to fight with each other.

How to Identify Koi Betta fish?

Simply you can see its body-based with cellophane and red and black spots on its body.

How koi betta acclimates?

Automatically koi betta fish tries to adapt to the freshwater within 5 to 8 min. But if it is a tank, it is good to keep a heater to take the water level into the same basis.

Do koi betta fish jump out of the tank?

Well, yes, Koi betta is good jumpers. They can jump to two to three inches approximately.

What do you do after your betta fish dies?

Take out the fish as soon as possible. Wrap it in paper and keep it in the freezer for a bit, helping preserve the body. Then burry the fish.

Common Health Problems

  1. Septicemia
  2. Columnaris
  3. Slime Disease
  4. Velvet
  5. Fin Rot
  6. Swim Bladder Disorder
  7. Popeye
  8. Constipated
  9. Tumor/Cyst
  10. Dropsy
  11. Fish Lice
  12. Hexamita
  13. Fungus
  14. Internal Parasite
  15. Ich
  16. scale loss

Also see our guide about Betta imbellis The Peaceful Member Of The Aggressive Family

Black Orchid Betta Care | Anabantoids | All You Need To Know

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About Dr.Chamika

Hello, I'm Dr. Chamika. I am a Researcher in Water quality, Aquatic organisms, and Environmental chemistry. I am a passionate fish keeper, with10 years of experience. My mission is to help other aquarists experience the joy of fish keeping.