Betta Fish Eggs 101: Everything You Need to Know

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Last Updated on 2023-12-30

If you’ve seen eggs in your bettas tank, then there are a million and one questions you’re going to be asking yourself. Fortunately, I’ve got you covered! I’ve been doing some deep research, and know everything there is to know about betta eggs!

So if you want to learn more, then keep reading! Or if you only have a quick question just look at the table of contents.

How To Tell If A Bettas Bubble Nest Has Eggs

When there are eggs in a betta’s bubble nest, they’ll look like white pearls which are roughly 1mm in size. Some may be round, whereas other may be more oval in shape. Over time, if these eggs are fertilized they’ll start to grow bigger, and have a grey spot in the middle.

(This grey spot is actually the fry slowly growing bigger and bigger.)

betta eggs

As you can see, when there are eggs in a bubble nest, the area with the eggs is going to be significantly whiter than the areas without. And if you were to look even closer you’d see all the individual eggs too.

What Does a Betta Fish Egg Look Like?

Betta fish eggs are usually laid on the surface of the water and may look like small bubbles or pearls. They are typically spherical in shape and can be seen in clusters of anywhere from 10 to 100 eggs. The eggs are usually attached to the underside of a leaf or a surface, such as a the corner of a tank.

betta fish eggs
Source: @vicki2780

When Betta fish eggs are fertilized, they will start to develop and will become slightly darker in color. After a day or two, you may be able to see tiny black dots inside the eggs, which are the developing embryos. The eggs will continue to grow and develop over the next few days, and you may notice that they become slightly more opaque and take on a yellowish color.

Why Are Eggs Kept In A Bubble Nest?

A betta will keep their eggs in a bubble nest, as it’s the safest place for them in the wild. It provides a clean, oxygen rich area, that stays moist, all of which are vital for the survival of the betta eggs. The nest also keeps all the eggs in one place so your betta can protect them.

Remember, bettas live in shallow, murky waters that are full of potential predators.

This habitat makes it difficult to lay eggs normally, so betta’s have adapted to form bubble nests to support their reproduction. The nest is similar to a cocoon where the eggs can grow safely under the protection of their dad.

How Long Do Betta Fish Eggs Take to Hatch?

On average, your betta fish eggs will take about three days to hatch, however this can vary depending on certain conditions in the tank such as:

  • Water Temperature: Water temperature is one of the most crucial factors that can impact the hatching timeline. The ideal temperature for breeding betta fish is between 80-86oF with 82-84oF being the most optimal.
  • Egg Quality: The quality of the eggs is another significant factor that can impact the hatching timeline. Fertile eggs should be slightly translucent, with a small, dark dot in the center. Cloudy or discolored eggs may be infertile or damaged, so of course, they won’t hatch.
  • Fish Health: The overall health of the fish is essential to the success of the hatching process. Before breeding, ensure that both the male and female fish are healthy and well-fed. Stress can also impact the quality of the eggs and the success of the hatch, so make sure that the fish are calm and relaxed throughout the breeding process.

What Do I Do When My Betta Fish Lays Eggs?

If you have a male and female Betta in the same aquarium, they may mate and lay eggs. When this happens, it’s important to take proper care of the eggs if you want them to hatch and survive. Here are the steps you should follow:

  • Keep The Eggs In A Separate Tank Or Divider: It’s best to move the eggs to prevent other fish from eating them. A divider can also be used to separate the breeding pair from the eggs.
  • Monitor Water Conditions: It’s important to keep the water conditions in the breeding tank or section of the aquarium consistent and suitable for the development of the eggs. Maintain a temperature of 80-82 degrees Fahrenheit, and keep the pH level neutral.
  • Provide Suitable Food for the Fry: Once the eggs hatch, the fry will need a suitable food source. Newly hatched brine shrimp or powdered fry food are good options. Make sure to feed them small amounts several times a day.
  • Keep the Tank Clean: Keep the tank clean to prevent the growth of harmful bacteria. Use a sponge filter to maintain good water quality, and perform regular water changes.
  • Observe the Fry’s Development: Observe the fry’s development closely, and remove any unhealthy or dead fry from the tank. As they grow, you may need to move them to a larger tank or separate them to prevent overcrowding.

How To Tell If Betta Eggs Are Fertilized 

If you want to know whether your betta’s eggs are fertilized or not, here are some of the signs to look for!

  • Fertilized Eggs Have a Gray Spot: One of the most distinguishing characteristics of fertilized Betta eggs is they develop a significant gray spot as they grow. Gray spots will be prominently displayed in the egg’s middle, making it easy to spot. Betta eggs can turn black, but they are still fertile. 
  • Eggs Turn Shades of Yellow and Brown: The white Betta eggs will soon develop shades of yellow and brown as they grow. As your eggs get closer to hatching, you can see the white yolk sac and a small fish inside. Since hatching time comes quickly, the betta eggs will start turning colors within the first day or two. 
  • Eggs Show Slight Growth: While fertilized betta eggs don’t grow immensely, they will develop a little before hatching. However, the growth is so slight that you may not even notice. An unfertilized doesn’t show any change because there is a lack of an embryo. 
  • Eggs Develop Two Black Dots for Eyes: Betta eggs are translucent; therefore, you can spot two black dots in the betta’s eyes. In about a day or two, you can see the eyes of the fertilized eggs. 
  • You Can See An Embryo In Betta Eggs: You can tell if a betta egg is fertilized by seeing the formation of a tiny embryo inside. The embryo grows fast and will be distinguishable rather quickly. 
  • Your Betta Will Care For The Eggs: Males will care for any fertilized eggs and are better caretakers than females. So, once the female lays the eggs, they can be removed, especially since they are prone to eat them if left unattended. 
red and blue betta fighting fish top form preparing to fight isolated black background

How Can You Tell If A Female Betta Has Eggs?

Signs of An Eggbound FemaleDescription
OvipositorSmall orifice located on the front underside of the female’s body behind the ventral fins. Turns noticeably white when the female is ready to drop eggs.
Check for StripesGravid female Bettas may develop 5-6 vertical lighter-colored stripes along the body, indicating readiness to release eggs. Stripes may not be perfectly defined.
Mild Abdominal BloatingGravid female Bettas exhibit a slightly wider abdomen as eggs grow. Noticeable change in the normal appearance of the female Betta. Be cautious of significant bloating, which can indicate egg binding, a potentially dangerous condition.
Bubble NestsWhile uncommon, some lone female Bettas may create bubble nests close to the water surface, a behavior typically associated with male Bettas.
Overall MonitoringRegularly observe changes in the color of the ovipositor, the presence of stripes, abdominal bloating, and any unusual behaviors like bubble nest

How To Care for Betta Fish Eggs

If you’re interested in breeding Betta fish, it’s important to know how to care for their eggs to ensure the best possible outcome for the fry. Here are some steps to follow when caring for Betta fish eggs:

  • Create A Breeding Tank: A separate breeding tank should be set up with a sponge filter and a heater to maintain a consistent temperature. The water should be kept at a temperature of 80-82 degrees Fahrenheit, and the pH level should be neutral.
  • Provide A Suitable Surface For Egg Laying: Once the eggs are laid, provide a suitable surface for them to attach to. A broad-leafed plant, such as Indian almond leaves or java fern, can be used. The male Betta fish will tend to the eggs and the bubble nest, protecting them from harm.
  • Monitor The Water Quality: Maintain good water quality by performing regular water changes and keeping the breeding tank clean. The eggs are sensitive to changes in water chemistry, so it’s important to keep the water parameters consistent.
  • Keep Them Aerated: Making sure that the eggs are remaining aerated is vital to hatching them. Not only will oxygenation help the fry grow, it will also help keep harmful bacteria from growing on them.
  • Feed The Male Betta Fish: During the breeding process, the male Betta fish may not eat. Once the eggs are laid, feed the male Betta fish small amounts of high-quality food to keep his strength up.

Should I Remove Female Betta After Laying Eggs?

You should remove the female Betta from the breeding tank after she has laid her eggs. If left in the tank, there is a risk that she will eat her own eggs or attack the male Betta who fertilized them. This can result in a failed breeding attempt and loss of potential fry.

Once the female has laid her eggs, carefully scoop them out of the breeding tank with a clean container and transfer them to a separate incubation tank filled with fresh water. The incubation tank should have a heater set at around 80 degrees Fahrenheit and an air stone to provide oxygen for developing embryos.

How Many Eggs Does A Female Betta Lay?

Generally, a female betta will lay between 30-100 eggs a time. However, this of course is a generalisation as it can be more or less. There are also things that can affect how many eggs your betta will lay too. Such as:

  • Age and Health:
    • Younger female Bettas produce fewer eggs due to developing reproductive systems.
    • Older females generally lay more eggs due to more developed reproductive systems.
    • The health of the female, if stressed or sick, may reduce egg production or skip cycles.
  • Breeding Tank Size:
    • Larger tanks provide more comfort during mating, potentially increasing egg production.
  • Frequency of Breeding Attempts:
    • Too frequent breeding or insufficient rest between cycles can decrease egg production.

Why Did Your Female Betta Lay Eggs Without The Male?

Healthy female Betta fish are always generating, developing, and carrying eggs in anticipation of mating with a male Betta fish. If the female Betta fish is living without any male Betta fish, she may release her unfertilized eggs. This can happen randomly, but there are certain circumstances that will increase the likelihood of the female dropping unfertilized eggs. These include:

  • If you are preparing your female Betta for breeding, it is likely that you will be giving her good quality fish food, which can help to promote the growth of eggs. The female may release her eggs prematurely rather than reabsorb them as they are not needed from a nutritional point of view.
  • If your female sees a male Betta fish, perhaps in a nearby tank, she may drop her eggs.
  • If your female Betta recently mated and produced fertilized eggs, she may release her eggs rather than reabsorb them as a conditioned response.
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How Do Betta Fish Eggs Get Fertilized?

Breeding Bettas can be a rewarding experience for those looking to expand their collection or simply observe the natural reproductive process of these beautiful creatures. But how exactly does it happen, and what factors affect their fertilization? Let’s find out.

The Reproductive Process

When it comes to fertilizing Betta fish eggs, you need both male and female Bettas. The male Betta will create a bubble nest on the surface of the water where the eggs will be laid.

The male Betta will then wrap his body around the female and squeeze her until she releases her eggs into the bubble nest. As she releases her eggs, he simultaneously releases his sperm onto them in order to fertilize them.

After fertilization has taken place, it’s important to remove the female from the breeding tank as she may eat her own eggs or attack any fry that hatch. The male will then tend to the eggs by protecting them from predators and keeping them in his bubble nest until they hatch.

Why Do Betta Eggs Not Hatch?

Unfertilized eggs, poor water quality, incompatible breeding partners, and suboptimal water temperature are common issues preventing betta fish eggs from hatching. Ensuring both fish are healthy, maintaining clean water, selecting compatible partners, and keeping the water within 80-86°F are crucial for successful breeding.

What Should I Do If The Eggs Don’t Hatch?

There’s a good chance you will have eggs that don’t hatch, even fertilized ones. Since female bettas lay dozens of eggs, the chance of not all of them hatching is high.

So if you’ve waited several days for them to hatch to no avail, these steps can help you with proper removal. Remember, sometimes it takes more than one attempt to remove unhatched eggs. 

  • Remove Eggs From The Tank: It’s crucial to take action if your eggs don’t hatch because rotting eggs can produce ammonia which can harm fish. You can remove them by vacuuming the bottle of your tank or using a net to pick up individual eggs.
  • Let The Male Eat Unhatched Eggs: As we know, males will get unfertilized eggs, and sometimes you can leave it up to them to take care of any unhatched eggs. However, you do want to be mindful not to let too much time pass to avoid bacterial growth in your tank.
  • Add Something That Will Eat The Eggs: If you want, you can also just add something that will eat the eggs. Most snails, shrimp and scavenger fish will do this!


Here are some frequently asked questions people have about their betta eggs!

Why Are My Betta Eggs At The Bottom Of The Tank?

  • Poor Water Quality: Dirty water can lead to betta eggs sinking due to high ammonia levels and contaminants. Hollow eggs bred in such conditions often end up at the tank’s bottom.
  • Extreme Temperatures: Improper temperatures can prevent male bettas from creating a bubble nest, causing eggs to rest on the tank floor instead.
  • Violence: Aggressive behavior among male bettas can destroy bubble nests, leading to eggs falling to the bottom of the tank.
  • Strong Currents: Powerful water currents can disrupt or break bubble nests, resulting in eggs dropping to the tank’s bottom.
  • Unfertilized Betta Eggs: Unfertilized or dead betta eggs are often ignored or eaten by the male, but sometimes they are left to settle at the tank’s bottom.

Do Betta Fish Eat Their Own Eggs?

Yes, it is possible for Betta fish to eat their own eggs. This can happen due to stress or lack of proper nutrition, among other reasons. To prevent this behavior, make sure your Betta has plenty of hiding places in the tank and provide a balanced diet with live or frozen food options.

Betta Fish Eggs 101_ Everything You Need to Know


And there you have it, folks! We hope you learned a lot about betta fish eggs and how to care for them. Breeding bettas and watching their eggs hatch is an amazing experience that any fish lover should try. Just remember to be patient and gentle when handling those delicate eggs. With the right care, you’ll have a batch of cute little fry in no time! So go ahead and give it a shot, and happy betta breeding!

Ultimate Betta Fish Care Guide
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