Pregnant Betta Fish: Most Common Questions Answered

As a Betta fish owner, it’s your responsibility to keep an eye on your little aquatic pet. Alongside providing them with the proper diet and environment, it is essential to know when your Betta can become pregnant. Imagine how cool would it be to see a tank full of swimming fry!

Okay, so let’s bring that imagination to reality. Betta fish don’t give birth to live fish, but rather lay eggs. Unlike most species where the female is in charge of taking care of her eggs, male Bettas take up the job.

They create bubble nests, carefully place the eggs, and then look after them until they hatch. That sure is a lot of hard work, isn’t it?

If you have plenty of questions running on your mind about pregnant Betta fish, this guide has all the answers! Keep reading to find out!

How Do You Know If A Betta Fish Is Pregnant?

Although synonymous with pregnancy, gravid is the actual term for species carrying eggs. If you’ve never dealt with a gravid Betta fish before, you might get confused as to whether or not your Betta is really going to lay eggs. To eliminate all the confusion, you can look out for these three pregnancy signs.

1. Vertical Stripes

The first sign of pregnancy is when your Betta has light-colored, vertical stripes along the body. The stripes might not have completely straight edges, but you can still tell that they’re vertical. There will be five or six stripes in total on both sides.

2. Mild Bulging Belly

Another obvious sign of pregnancy is when the Betta has a mild bulging belly. The increased stomach is more noticeable from above than sideways. As long as constipation and being overweight have nothing to do with the swollen belly, it is a clear indication that your Betta is carrying eggs.

3. Color Change Of The Ovipositor

The ovipositor is the small white spot located behind the ventral fins. It is actually a tube through which eggs are ejected into the water. If you’re unsure of whether your Betta is a female, you can look for this ovipositor.

How Long Do Betta Fish Stay Pregnant?

Generally, Betta fish remains in a gravid state for one or two weeks. When the Betta releases the eggs in presence of a compatible male Betta fish, the male fertilizes the eggs. After fertilization, the eggs hatch into fry within five days.

Newborn fry are unable to swim, so if they accidentally fall out of their nest, the male Betta will put them back until they grow up.

Can Betta Fish Lay Eggs Without A Mate?

Betta fish naturally produce eggs in the ovipositor. They can release the eggs even if there’s no mate around. In that case, the eggs won’t be able to hatch but sink to the bottom of the tank.

As the eggs remain abandoned, they will rot and cause a rise in ammonia and nitrite levels. High levels of these chemicals are dangerous for fish as they can affect the gills, tissues, and organs, leading to death.

However, if the Betta consumes the eggs, then water pollution shouldn’t be a problem.

What Should I Do If My Female Betta Lays Eggs Without A Mate?

If there isn’t any male Betta fish in the same aquarium as your female Betta, the eggs won’t be fertilized. It can be a problem if the female Betta doesn’t reabsorb the unfertilized eggs. Those eggs will rot in the tank and release toxic chemicals that are harmful to your Betta.

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If you ever notice eggs lying in the bottom of the tank, make sure to vacuum them. Frequent cleaning will reduce the risk of pollution as the unfertilized eggs will be removed. Also, make sure to feed your Betta normally and monitor the water parameters.

Can I Keep Male And Female Betta Together?

Keeping male and female Betta fish in the same aquarium is a big no-no unless you want them to breed. That’s because male Betta fish typically tend to get more aggressive towards their female counterpart. Keeping them together can result in injury to the female Betta fish.

Oftentimes during or after the breeding session, the male Betta can become aggressive. If that happens, then you’ll need to keep them in separate tanks. For the sake of safety, we recommend expert fish-keepers initiate the breeding session. 

What Do Betta Fish Eggs Look Like?

Unfertilized Betta fish eggs are white in color and measure about a millimeter. They aren’t fully round but more like an oval shape.

However, mouth-brooding Betta can produce larger eggs of about three millimeters. The male Bettas of this type tend to hold the fertilized eggs in their mouth until it’s time for the fry to come out. It takes longer for these eggs to hatch compared to normal Betta eggs. As they develop, the eggs turn yellow and then start to darken.  

How Do I Know If My Betta Eggs Are Fertile?

While unfertilized Betta eggs are fully white, fertilized eggs have a small grey spot in the middle. When the eggs grow larger, it will indicate that fry will come out at one point.

How Long Does Betta Fish Eggs Take To Hatch?

Normal Betta fish eggs typically take about two or three days to hatch, while mouthbrooder Betta fish eggs can take longer up to a month. The exact hatching period depends on a couple of factors- temperature and water quality.


As Betta eggs develop into the water, the temperature of the water plays an important role in the process. Betta fish usually have increased metabolism and digestion rate at higher temperatures and decreased metabolism and digestion rate at lower temperatures.

So, the eggs developing at higher temperatures above 75 degrees Fahrenheit, will hatch faster than those in colder temperatures.   

Water Quality

Water quality is an obvious factor that can affect the development of Betta eggs. With the right water parameters, there’s a high chance of faster hatching.

But if the water is polluted with Betta’s natural waste and microorganisms, then there will be a rise in ammonia, which can be toxic to the eggs. Apart from that, there can be other toxic substances. Unless you change the water regularly, the harmful chemicals will damage the eggs.

If you’re aware of the water parameters and perform a regular water change, then the eggs should be safe.

After hatching, Betta fry don’t start swimming instantly. They remain under their father’s observation for a couple of days before becoming independent. If they fall out of the nest, the father Betta will pick them up and put them back.

How Do I Know If My Betta Is Making A Bubble Nest?

Male Betta fish are responsible for making a bubble nest for their offspring. They first use their labyrinth organ, a special type of organ present in anabantoids for breathing air, to make bubbles. After that, they protect the bubbles from popping by using their saliva.

The reason why they make these bubbles is that they are filled with an ample amount of oxygen suitable for the development of eggs and fry. Not only that, but also they provide protection. Bettas are most likely to create a nest under a floating leaf to protect it from the eyes of predators.

If you ever see your male Betta fish getting busy with bubbles near the surface of the water, it is a clear indication that the fish is creating a nest.

Should I Remove Betta Bubble Nest?

You might be surprised to know this, but your Betta won’t react if you destroy its bubble nest, whether deliberately or accidentally. Regardless of the number of times you remove the nest, the Betta will always attempt to build a new one. But still, if you love your little pet and appreciate its hard work, it’s a good idea to leave the nest as it is.

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When Do I Remove Male Betta From Fry?

The male Betta fish is there to build the bubble nest and protect the eggs until they hatch. It takes about two or three days for the fry to come out of the eggs and swim on their own. If left with the fry without any food, the male Betta might snack on them. Therefore, it is a good idea to remove the male Betta as soon as you see the fry swimming around.  

Do Betta Fish Eat Their Babies?

Betta fish tend to eat their babies mostly if the eggs aren’t well-fertilized or there’s no food around. Although eating fry isn’t a common sight, there are a few other factors that can cause the Betta to turn into a bad parent.

Aggressive Betta Parent

Betta fish are known to be naturally aggressive, but when it comes to raising their young, the male Betta do so with care.

However, the opposite can happen if the male Betta has persistent aggressive issues. Such Bettas fail to care for their young and eat them even before hatching. While it is possible for them to be a good father after giving several chances, not all can make it.  

Presence Of The Female Betta During Spawning

Female Bettas tend to consume their eggs if they are left for too long after spawning. Male Bettas are very overprotective towards the bubble nest, and if female Bettas try to attack them, they can become aggressive and even kill them. That’s why breeders think that removal of the female Betta after spawning is a must.

Stress And Confusion

When Bettas are left to spawn in an environment that is different from their natural habitat, they can become stressed and confused. As a result, both the male and the female can start consuming their eggs.

How Many Babies Can Bettas Have?

Typically, Betta fish lay about 30 to 40 eggs per spawn. There are some Bettas that can even lay as many as 500 eggs per spawn. The number of eggs a female Betta can lay largely depends on how it is conditioned. The more well-conditioned the Betta is, the more eggs will be produced.

How Do Betta Fish Make Babies?

Betta fish make babies through external fertilization, which means the female will lay eggs, and the male will fertilize them.

The breeding process starts with the male Betta building a bubble nest near the surface of the water. Then when the female is introduced, she will take a look around the nest, and if it is built according to her liking, she will proceed with mating. If she isn’t happy with the nest, then she is likely to destroy it.

The male Betta will then wrap himself around her, and then extract the eggs. Once they come out, the male will release milt to fertilize them. After that, the male Betta will collect the eggs in his mouth and carefully place them into the bubble nest. He will put the eggs in observation until the hatchlings are ready to swim.

Is A Big Belly On A Betta Always A Sign For Pregnancy?

Oftentimes constipation and belly fat in Betta fish can be mistaken for pregnancy. If it’s constipation, then feeding your Betta a small portion of blanched pea will alleviate the issue. In this situation, it is a good idea to avoid flakes as they stimulate constipation.

If you think your Betta has belly fat, you can reduce the amount of food that you would normally feed her. Sometimes bloating can also happen as a result of consuming live food. In that case, you can give her fish medicines.

However, if you ever notice a white spot behind the ventral fins alongside a bulging belly, that’s a clear indication that your Betta is pregnant.

How To Make A Female Betta Fish Produce Eggs?

If you want your female Betta to produce eggs, you can try the following tips.

  • Condition her well with high-protein foods, such as bloodworms and brine shrimp. You can also feed insects. These foods will help them gain strength and produce eggs.
  • Ensure that she is swimming in clean water with the right parameters.
  • Make sure the breeding tank is large enough. It should have a capacity of at least 10 gallons.
  • Keep her with a male Betta fish that is at least 14 months old. You can start off by using a tank divider. If there’s any sign of aggression upon introduction, you should place them in separate tanks.
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Once she is gravid, you can place her in a separate aquarium decorated with several plants to keep her stress-free.

What Does Baby Betta Fish Eat?

Baby Betta fish will start looking for food as soon as they hatch. Unlike adult Betta fish, Betta fry like to consume only live food. That includes-

  • Brine shrimp
  • Daphnia
  • Mosquito larvae
  • Tubifex worms
  • Infusoria
  • Grindal worms
  • White worms
  • Black worms

As they grow older, you can introduce them to crushed pellets and frozen food. Unless the fry are very young, it is recommended you feed them at least a couple of times a day. 

Do Betta Fry Need Night Light?

Betta fry can’t see very well in the dark. They might have difficulty finding food if there’s no night light. It is recommended you keep the night light turned on for the first four or five days after they are separated from their father.

After that, you should provide your Betta fry with 12 hours of light per day. If they remain constantly exposed to light for more than 12 hours, they can become stressed. Make sure that you don’t expose the little ones to direct sunlight as it can lead to tank overheating, excessive algae growth, and health issues. 

How Do You Take Care Of Baby Betta Fish?

After the father Betta is removed from the tank, it’s your responsibility to take care of the fry. Here’s what you can do.

1. Keep Each Of Them In Separate Tanks

Baby Bettas are small and so they are easy to get picked on by their tank mates. To prevent such from happening, it is recommended you keep each fry alone in separate tanks. The tank should hold a minimum of a gallon of dechlorinated water so that the fry can grow properly.

When the fry reaches adulthood, you can introduce them to other tank mates. If they show aggressiveness towards other fish, then it’s a good idea to keep them separate.

2. Nourish Them With Different Kinds Of Food

Betta fry depend on live food for their survival. You can feed them grindal worms, white worms, and brine shrimps. When they grow a little bigger, you can introduce them to crushed pellets. Although Betta fry tend to eat a lot more than adult Bettas, make sure to feed them a limited amount of food.

If the tank is overloaded with food, the fry might eat too much which would result in swim bladder disease. Also, the water can become contaminated. You can find Betta fry foods online or at your local pet store.

3. Ensure The Right Temperature

Betta fry can’t survive at extremely hot or cold temperatures. The ideal water temperature for them is around 27 degrees Celsius or 80 degrees Fahrenheit. Colder water can lead to health issues, like loss of appetite, so the water needs to be brought at the ideal temperature using a small heater.

4. Replace The Tank Water More Often

It is also important that you always keep the fry in clean water. That means you should change the tank water frequently. After filling in the tank with fresh water, make sure it is set to the ideal temperature. Otherwise, the Betta fry can go into shock.

5. Add Sponge Filters

A sponge filter can be beneficial as it helps in keeping the tank water clean. When choosing a sponge filter, make sure it is of high quality and also doesn’t cause injury when the fry come in contact with it. Also, make sure it doesn’t cause the water to flow at faster speeds.

When Do You Separate Betta Fry?

Male Betta fry should be separated from themselves when they reach eight or nine weeks of age. That’s because they tend to show aggression and territorial behavior if kept with other male fries. At this stage, their color becomes more vivid and their fins get longer.

As for the female Betta fry, they can get along well with others. However, once they get into a fight, they can get aggressive and inflict more damage than their male counterparts.


So, that’s all we had to share about pregnant Betta fish. Alongside, we’ve also talked about Betta fry and how you can take care of them. If you’re interested in increasing the Betta population at home, hopefully, this guide can be of some help!

Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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