Betta (Siamese Fighting Fish)

Betta fish (Betta splendens) are beautifully colored, tropical, freshwater fish that are native to Southeast Asian countries like Thailand, Cambodia, Laos, and Vietnam.

Commonly known as the Siamese fighting fish, bettas are infamous for their aggression.

Despite their aggression, bettas are still one of the most popular and sought-after types of fish for fishkeeping enthusiasts. Betta fish tend to have vibrant colors and long, flowing fins that many aquarists find captivating.

Bettas are a bit harder to maintain than other aquarium fish, so make sure you do your research and make adequate preparations regarding betta fish care before bringing one home.

See also: crowntail betta and paradise betta

Betta Fish Facts & Overview

Betta fish near the surface

Care Level:Moderate
Color:Various colors, patterns, and shapes
Lifespan:~3 years
Size:~2.5 inches
Minimum Tank Size:10 gallons
Tank Setup:Freshwater, plants, caves
Compatibility:None, or peaceful, shoaling species

Bettas (Betta splendens) are one of the most well-known tropical fish in the fishkeeping world.

They belong to the Osphronemidae family. This means they are closely related to other popular aquarium fish, such as gouramis.

Bettas are native to Asia and are most commonly found in Thailand, but they also live in Laos, Cambodia, and Vietnam. Although they are one of the most common fish in home aquariums, they are listed as a vulnerable species in the wild.

The lifespan of betta fish is relatively short. A healthy individual in a clean tank usually lives for around three years.

Because bettas are so popular, nearly every pet store sells them, so you won’t struggle to find one in your area. You can find individuals for roughly $5, but this price could more than double depending on the store and the various types of betta fish.

They come in many different variations and are usually classified by features such as colors and patterns.

While some bettas are captured in the wild, there is growing concern that more and more betta fish are sourced from breeding farms in Thailand to meet the growing demand. These fish are bred and kept in horrid, unsustainable conditions, so please do your research into safe, sustainable fishkeeping practices before buying a betta.

Typical Behavior

Bettas are often called Siamese fighting fish due to their aggressive tendencies. Before the 20th century, they were even bred for fighting.

Both males and females will flare their gills to intimidate rivals. Even on their own, they will establish a territory and defend it. Because of this, most people keep them without tank mates to avoid this aggression.

Female bettas like their own territory, but they are less prone to fighting than male bettas. This makes them more suitable for a community tank.

When not having to compete with rivals, most of the time they will slowly swim around the middle and upper levels of your tank.

Bettas are diurnal, meaning they are active during the day and sleep at night.

Do Bettas Breathe Air?

Betta fish have gills paired with something called a labyrinth organ which allows them to extract oxygen from the air, so technically they breathe both water and air.

This organ is important because, in the wild, bettas would often be forced to survive in shallow puddles if their habitat evaporated during the dry season.

Types and Appearance

Red betta fish showing its fins

Bettas are some of the most beautiful tropical fish around. Not only are they incredibly colorful, but their fins are large and majestic.

They have been extensively cross-bred, so there are many types of betta fish. Their tails are a particularly attractive feature, and they come in a few different styles.

One example is the crowntail betta. This species has fins covered in spikey extensions that resemble a crown. If the spikes reach 2/3 of the way up the tail, then the individual is technically classed as a combtail betta.

Veiltail bettas have long, flowing tails without extensions. This variety is particularly vibrant because the fins are a solid color.

An individual might have more than one color. Bettas can even have two, three, or more colors. These colors could be solid, speckled, marbled, or even resemble other fish like a koi fish.

The colors of a betta intensify when fighting (to intimidate a rival) and when breeding (to impress a mate).

Male and female bettas are quite easy to tell apart, as they exhibit sexual dimorphism. Females have smaller bodies and fins, and the vibrance of their colors is greatly reduced as well. Females are less extravagant compared to male bettas, but they are still attractive fish.

Bettas usually grow to around 2.5 inches in length.

Betta Fish Care

A majestic crowntail betta

As responsible fishkeepers and aquarists, our job is to simulate their natural habitat as much as possible in our tanks at home so that our bettas can live healthy, happy lives. This means ensuring that our bettas have enough space to swim, warm enough water, enough light and darkness, and nutritious, varied food that it likes to eat.

Habitat and Tank Conditions

Betta fish and its habitat

Bettas are tropical fish endemic to several countries in Southeast Asia. They typically live in small, shallow streams, ponds, and rice paddies.

The waters they live in are generally slow-moving, warm, and full of vegetation.

Tank Setup

Use fine gravel or sand as a substrate to cover the bottom of your betta fish tank. Place some decorations on top of the substrate, and try arrange some caves to act as separate territories.

Spread some plants around the tank too. Along with emulating the betta’s natural environment, these plants will provide shelter and oxygenate the water. Don’t let the plants block large areas of the surface. Bettas head to the surface to breathe, feed, and breed.

Most plants pair up well because they prefer similar water conditions. Some of the best plants for betta fish are the Java fern and hornwort, as beginners can easily care for them as well.

You will need a heater to bring the water up to a suitable tropical temperature. Keep this in the range of 75–80°F.

The water’s pH should be 6–8 and hardness should be 5–35 dGH.

Your betta tank should have a filter, though it is not absolutely necessary if you commit to changing the water twice a week. Water and air pumps aren’t necessary because bettas are used to almost still water.

You might want to invest in some LED aquarium lighting as well.

Do Betta Fish Need a Filter?

Yes, bettas should have a filter in their tank. If you want to go without a filter, you’ll need to change the tank water at least twice a week. Your fish will start to die if they go for an extended period of time without a filter or frequent water changes.

Of course, there are other reasons for your fish becoming ill, and it just takes a bit of investigating to find out why. Explore all of the common reasons why fish may die, and identify ways to prevent it from happening again.

What Size Aquarium Do They Need?

If kept alone, bettas need at least a 10-gallon fish tank. If you are mixing them with other fish species, they will need extra space so they can swim freely, claim territory, and defend it.

Give each female betta at least five gallons, but ideally more.

Compatibility and Tankmates

A neon tetra as a betta fish tank mate

Choosing betta fish tank mates can be difficult because of their aggression, so you might be surprised to hear that bettas can go in community tanks. In the wild, they would mainly live solitary lives, but they would still encounter fish without confrontation.

Tetras make good companions in an aquarium because it’s hard for one fish to be bullied repeatedly. They are usually faster too, so they can escape a territorial species.

There are lots of possible tank mates, including neon tetras, endlers, fire rasboras, cory catfish, short-fin mollies, celestial pearl danios, kuhli loaches, White Cloud Mountain minnows, glass catfish, and yoyo loaches.

Avoid fin-nipping species (like tiger barbs) because your bettas have large fins. You also don’t want to introduce another territorial species (like oscar fish), as they will start to compete.

Female bettas are less likely to attack the rest of your fish, but you should still stick to the guidelines above when choosing tank mates.

If you don’t want to risk adding other fish, you could opt for some invertebrates. Cherry shrimp and nerite snails are just a couple of options.

Keeping Betta Fish Together

The safest option is to keep males on their own. You should definitely only have one male per tank.

Females have been found to display similar aggression levels, but they are usually much calmer, so it’s safer to keep females together.

A group of at least four females is called a sorority. Females need their own space just like males, so if you want a sorority, you need a big enough tank (30 gallons) to give each of them their own territory.

Only introduce a male to a female when they are ready to breed.

Diet and Feeding Requirements

Bettas are carnivores, so the best betta food includes plenty of protein.

In the wild, they would eat any small animals that pass their ways, such as worms, daphnia, bloodworms, brine shrimp, mosquito larvae, and even other fish.

There are many options to choose from when recreating this at home.

The simplest choices are flake and pellet foods. These are found in all pet stores and aim to provide the nutrients they need.

More nutritious options are freeze-dried foods, or better yet frozen or live foods. All three involve using the same creatures, but freeze-dried foods have had the moisture and some of the nutrients removed.

Bloodworms, brine shrimp, and daphnia are some popular creatures that come in each form.

Bettas will keep eating until there is nothing left, so be careful not to over-feed them. Feed them an amount that they can easily finish within two or three minutes.

Feed your bettas twice a day. Spreading the feeding out makes it easier for their digestive system to handle.

Betta Fish Not Eating

If your fish aren’t eating, it’s usually because they are sick.

Another possible explanation is that they don’t enjoy the food you are giving them. This could be because of their personal preference, or the food isn’t suitable for betta fish in general.

Try switching up the diet to see if the situation improves.

Sick Bettas

Although they are one of the hardiest aquarium fish, bettas can still get sick just like any other fish.

Infections are the most common problem. Your betta may also pick up injuries when fighting with other fish. These injuries may open up cuts, leaving them exposed to infections. The same can also happen with sharp substrates and decorations.

You can go some way toward preventing disease by keeping your tank properly maintained. You need to know how to properly keep your tank clean and perform regular water changes.

You’ll need to change 20% of their water every week.

However, even with a clean tank and healthy living conditions, your bettas still may become ill.

Fin Rot

Fin rot is a common disease that can affect most fish. It’s a bacterial infection that causes inflammation and irritation. Fin rot either develops in unclean water or is introduced to the aquarium, but it is always environmental.

Symptoms of fin rot include discoloration on the edges of the fins or tail. As the disease spreads, pieces of the fins and tail may die and fall off. Eventually, fin rot will kill the affected fish.

While it’s relatively easy to prevent, fin rot is difficult to cure, so you should strive to maintain and clean, healthy tank for your bettas.


Bloat goes by many names: dropsy, edema, and Malawi bloat for cichlids. Bloat is a condition where the abdomen swells and the scales stand out. This results in breathing difficulties, loss of appetite, and lethargy.

Bloat can be caused by bacteria, viruses, or parasites. However, the usual cause is overfeeding. Ration their diet and watch if the swelling goes down.

Betta Breeding

Bettas breeding near the surface with a bubble nest

Breeding betta fish is one of the few occasions where you should introduce two bettas together.

Breeding can be difficult, as their environment needs to be perfect and they need to be conditioned for a couple of weeks in preparation.

Preparing your bettas for breeding involves feeding them high-quality, live foods in small amounts 2–4 times a day. The tank temperature should be at the higher end of their preferred range (75–80°F), and the water should be kept clean.

After this, you can introduce the female to the male. Add the female using either a divider or floating her in a see-through container.

If the female is interested, she will darken in color and display vertical stripes. If the male is interested, he will darken and start to build a bubble nest.

Betta Fish Bubble Nest

Male betta fish build bubble nests within 24 hours of seeing a suitable female. The bubble nest is made from air bubbles that are covered in saliva to make them sticky and durable.

These bubble nests are often built at the surface or objects near the top of the tank.

Once the nest is made, you can release the female. She will probably head straight to the nest for inspection, and if the nest is not good enough, she might destroy it.

The pair will start to court with some impressive displays. This might involve chasing and biting each other, so be ready to intervene if things get aggressive. The male will then flip the female upside down and wrap himself around her to fertilize her eggs as she releases them. This may go on for up to a few hours.

The male will catch the eggs and take them up to the nest.

Cover the tank in plastic wrap to make the aquarium humid enough to encourage the fry to hatch.

Hatching should occur over two or three days. It will be another four months before the fry hit adulthood.

Are Bettas Suitable For Your Aquarium?

When keeping bettas, you have to be careful and plan everything around their aggressive nature.

If you are committed and able to maintain a tank that is as close to their natural habitat as possible, bettas may be a good choice for you. However, due to their aggression and care requirements, keeping betta fish may not be suitable for beginners.

Your job as a responsible fishkeeper is to keep everything clean, so your betta fish can stay happy and healthy. If you feel confident you can do this, a betta is suitable for your aquarium.

They are an interesting species with plenty of personality, so make sure you choose a betta fish name that matches!

Frequently Asked Questions About Bettas

About Robert 387 Articles
Robert Woods is the creator of FishKeeping World, a third-generation fish keeper, and a graduate in animal welfare and behavior. He is also a proud member of the Association of Zoos and Aquariums, the Marine Aquarium Societies of North America, and the Nature Conservancy.


  1. Jen Bingham says:

    Hi, new Betta owner here. I have kept water frogs over the years and also a few different types of fish. I had a 1 gallon tank already with decorations, gravel, everything I thought I needed. Got him home and realize my 3 gallon tank would be much nicer for him. I want to get rid of the gravel, and use tumbled crystal pebbles. Would this be ok for my Betta? Also have a heater and filter on the way. Should be here in 3 days. Is there anything I can do to keep the tank warm enough in the mean time?

  2. Johann "Hans" Fischer says:

    I have my Elephant Ear BETTA in a 110 Gall. Community Tank with medium sized Discus, Neons, multible kinds of Cory Cats, Yoyo Loaches, Kuli Loaches, Glo Tetras and a 10 inch Pleco – all in perfect Harmony!!!

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