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Home > Betta fish > Koi Betta (Marble Betta): Care, Varieties & Lifespan

Koi Betta (Marble Betta): Care, Varieties & Lifespan

male koi betta fish

If you have seen the koi betta, otherwise called the marbled betta, you can see how they got their name. These bettas have the same erratically spotted patterns as Japanese koi fish.

If you have ever owned a betta fish before, you’re already up for the challenge. But, if you haven’t, we will discuss primary care and requirements to keep this fish happy and healthy throughout its lifetime.


Quick Facts about Koi Betta

Species Name: Betta splendens
Family: Betta
Care Level: Easy
Temperature: 75 – 85 degrees F
Temperament: Aggressive
Color Form: Black, orange, white
Lifespan: 3 years
Size: 3 inches
Diet: Carnivores
Minimum Tank Size: 10 gallons
Compatibility: Low

Koi Betta Overview

The koi betta fish were initially known as marbled bettas, but as their intensity and color pattern transformed—so did their name. As a result, the koi betta resembles the infamous Japanese koi carp. However, the two aren’t directly related.

Koi bettas have the loveliest color patterns, ranging from white, orange, and blue hues. They have a calico-like appearance, waving their fins with elegance and grace. It is a stunning color that sets them apart from the rest.

Males and females look different, as most males are flashier and more flamboyant than the ladies. That is because they literally fight over the females in the wild, so they require extravagant displays.

koi betta fish
Image Credit: Paisit Teeraphatsakool, Shutterstock

How Much Do Koi Betta Cost?

Koi betta fish are generally a little more than traditional types. You can expect to spend between $12 and $20.

You might also be able to find a koi betta fish in need of a new home. Sometimes, they can be free, while others may charge a small fee for the entire setup.

On top of your initial purchases, you also have to keep in mind all the supplies you’ll need for total care.

If you don't have these items already, you'll need to pick each one up before you bring them home:
  • 10-gallon tank (or larger)
  • Commercial betta fish food
  • Substrate
  • Water pH balancer
  • Plants (optional)
  • Filtration (optional)
  • Décor (optional)

Typical Behavior & Temperament

Bettas have quite a reputation for being—well, spicy little buggers. They don’t get along well with like species and only make decent matches for a few tankmates.

Bettas are also called Siamese fighting fish because they aggressively chase off opposing males who want to interfere with their territory.

Sometimes, females can live in a small group peacefully, but this possibility is a gamble. Therefore, as a precautionary measure, bettas should only be together during mating.

As for entertainment, you can spend time watching your betta zip across the aquarium with zeal. These fish are inquisitive and active—and they might even follow your finger against the glass.

koi betta fish male
Image Credit: Ron Kuenitz, Shutterstock

Appearance & Varieties

The koi betta started as the marbled beta—and it was slightly more diluted than the koi bettas you might see today. These fish have vividly colored flowing fins with hues of orange, red, yellow, white, and black.

Males tend to be a little more extravagant and eye-catching than their female counterparts. For example, female koi bettas have shorter fins and smaller bodies—but the color stays just as vibrant.


How to Take Care of Koi Betta

Providing the right aquarium and additives is essential for the livelihood and wellbeing of your betta. Here’s how to set things up.

Habitat, Tank Conditions & Setup 

  • Aquarium Size – 3 gallons: Betta fish are often sold in tiny containers. It’s commonly widespread knowledge that they also don’t necessarily require a filter in their tanks. Because of their modest space requirements and inexpensive aquarium, these fish are favorites.
  • Water Temperature – 70-85 degrees F: Bettas are tropical fish that love warm water. Room temperature works fine in most cases, but they love temperatures as high as 84 degrees. So keep bettas away from any drafts or windows in colder months.
  • pH – 6.8-7.5: Bettas need the correct water pH to stay healthy. Therefore, you should always test your water pH to make sure it stays within these parameters.
  • Substrate – Gravel, sand: Bettas typically only eat what they can fit in their mouth. Therefore, having sizable gravel is an excellent substrate because the granules are generally too big to ingest. Sand is also a good alternative—and it also gives your tank a natural aesthetic.
  • Plants – Coontail, leptochilus pteropus, java moss, water weeds: Your betta will love playing hide and seek in the plants around their aquarium. These additions keep the water cleaner longer.
  • Lighting – LED lights: Betta fish don’t need any heat lighting, but it is nice to put an LED light onto the enclosure to mimic natural daytime/nighttime cycles.
  • Filtration – unnecessary: Bettas don’t necessarily require filtration, but it does help keep the tank clean. Filters are optional—and sponge filters generally work best.
koi betta fish
Image By: pussit nimnakorn, Shutterstock

Are Koi Betta Good Tank Mates?

You cannot have multiple male betta fish together in the same enclosure. It’s also a good idea to keep fish with flowing fins out of the aquarium too.

Koi bettas work best alone. However, if you’re certain you want a full tank of little swimmers, here is a few pairing that should work out:

  • Cory catfish
  • Kuhli loach
  • Suckermouth catfish
  • Guppies
  • Mollies
  • Cherry shrimp
  • African dwarf frogs
  • Tetras

All bettas need compatible living mates that require the same water requirements.

nemo koi betta
Image By: lmstevendesign, Pixabay


What to Feed Your Koi Betta

Koi betta fish are predatory creatures that eat animal material. They will eat a standard diet of pellet food—but you can give them a variety of live foods to snack on, too.

Some betta favorites include:
  • Mosquito larvae
  • Daphnia
  • Bloodworms
  • Earthworms
  • Brine shrimp
  • Small fish

Some betta fish can be particularly picky, so you will soon learn their favorites—and you can feed them accordingly.

Keeping Your Koi Betta Healthy

Your betta fish will live a very long time with proper care. However, there are specific issues to look out for when you own these fish.

You can keep in touch with local aquarists for advice on treating any illnesses that may pop up. Environmental factors are usually the culprit in disease, closely followed by diet.

Some common issues koi betta fish might face include:
  • Hole in the head
  • Ick
  • Swim bladder disease
  • Pop eye

To prevent health problems from rising, make sure your betta has a suitable environment and diet schedule.


Breeding can be profitable, permitting that you do things correctly. However, since these fish can be quite testy toward one another, close supervision is essential. Once the deed is done, the male and female should separate once again.

When you introduce the pair, the male will start building a bubble nest within about an hour. If females love the nest, all is golden. If they don't, they might reject breeding or become disinterested in the male.

The mating process can take up to 6 hours. After that, each of them will partake in mating dance rituals and then finally finish the process.

Once the female releases the eggs, the male places them gently into the nest one by one. Interestingly, mom doesn't stay around after the egg release. Therefore, it would be best to move her into another enclosure, as the pair could fight to the death.

The male will tend to the eggs for about 3 days until they finally hatch. Once they do, dad's job is done, and you can move him out of the baby's tank, too.


Are Koi Betta Suitable For Your Aquarium?

Koi betta fish make charming additions to many tank setups. However, these fish work best alone—so if you have existing fish, make sure they are compatible or set up other arrangements.

Koi bettas are visually stunning, active fish that you will appreciate. These fish are perfect for first-timers and experienced hobbyists alike—enjoy!

Related Betta Reads:

Featured Image Credit: Ron Kuenitz, Shutterstock

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