How to Tell if a Betta Fish is Pregnant

How to Tell if a Betta Fish is Pregnant- 5 Tell-tale Signs

Betta fish, also known as Siamese fighting fish (Betta splendens), originates from South East Asia. You will find the wild betta fish in slow-moving streams and shallow channels.

However, the betta fish we keep as pets come from breeding farms in Thailand, and many aquarists aren’t experts in breeding. As that’s the case, this article will discuss various ways to tell if a betta fish is pregnant.

Despite being the most popular pet breed globally, little is known about betta fish reproduction. Unfortunately, new aquarists are directed on how to introduce males to females but not taught about their reproduction habits.

Moreover, few aquatic pet shops will guide you on how to tell if a betta fish is pregnant. Thankfully, you will have five sure ways to tell if your beautiful female fish is pregnant by the end of this writing.

Read on also to answer the popular question, “how do betta fish get pregnant?”

Saying “Betta Fish is Pregnant” is Misnaming

black and orange betta fish
Betta fish

Bettas are in the category of spawning fish. Spawning means the fish are egg layers. To be clear, betta female fish release eggs later fertilized by the males outside their bodies.

After fertilization, the females aren’t nurturing mothers. Instead, they leave the role of rearing to the males.

Well, betta fish don’t become pregnant because they don’t give birth to young ones. They lay eggs that hatch to young betta fish.

As such, a good term for a “pregnant” betta fish is Gravid fish. Gravid is a term that describes sexually mature female fish that carry eggs ready for fertilization.

So, “can betta fish get pregnant on their own?” Instead of getting pregnant, let me describe it as becoming gravid.

Yes, once the females are mature for reproduction, the eggs develop in their bodies without the involvement of males.

How to Tell if a Betta Fish is Pregnant

There are five ways to tell if a betta fish is pregnant. However, observing one sign may mislead you.

Instead, combine the whole five signs, and you will be sure enough that your fish friends are gravid.

And without further ado, let’s dive in and learn the five signs.

1. A Little Bloating

“Is my betta fish pregnant or fat?” This sign may be a bit confusing. In fact, new owners conclude that the fish are constipated.

However, constipation comes with other signs like betta spitting out their food and becoming inactive. Although a little bloating may arouse fear, it’s a good sign that your betta fish may be pregnant.

As such, you will notice abdominal rounding due to eggs that have formed in the body. Additionally, it’s more noticeable when you view them from above rather than from the side.

Further, it will be easier to notice if you interact with the fish regularly.

Take note; you shouldn’t worry about betta fish pregnant without males because you have learned above males fertilize the eggs outside the female body.

2. Strips on the Body

The second sign of pregnancy in female betta fish is vertical stripes on their bodies. The strips have a lighter color compared to the original body color.

blue and white fish in aquarium

In addition, the strips are around five, and you will notice they are jugged on the edges.

However, some females may not develop these strips. So, it’s good to observe other signs to conclude that the fish are pregnant.

Read: What to do for a stressed betta fish

3. The Ovipositor

You will notice a white spot on the underside front half of the betta fish body. This is known as an ovipositor.

To clarify, the ovipositor is found behind the vertical fins and in front of the anal fin. This white spot also bulges outward, indicating that the fish are ready to lay eggs.

Note that this egg-laying organ is just a small surface you may not quickly notice. Instead, you need a precise observation through the glass tank.

Another opinion is you can transfer the fish into a clear glass and search for the ovipositor sign.

Read: How to clean a 3 gallon betta fish tank

4. Male Creating Bubble Nests

If you have kept males and females in the same tank, you will notice the males are creating bubble nests on the fish tank water surface.

However, keeping both females and males in the same tank isn’t a good idea. The male betta fish is well known to be territorial.

Ideally, introduce them to females for reproduction purposes only.

That aside, males spit out a series of bubbles on the water surface, creating nests. These nests hold the eggs for fertilization and secure them until they hatch.

Read: How can I tell if my betta is stressed

5. Female Behavior Change

When the females are ready to lay eggs, you will notice they are attracted to males and their nests.

Usually, the females will inspect the nests before laying the eggs. If they don’t like them, they will destroy them, and the males will build others to impress them.

Finally, if the females like the nests, the males will come near, and they will have a rough union that seems like little fighting.

Then, the males will curve over the females in a horseshoe shape and squeeze the area around the ovipositor to help the female fish lay the eggs.

FAQs on Betta Fish Eggs

How Male Betta Fish Take Care of the Eggs

After the females have laid the eggs, males chase them away. In 2 to 3 days, they will replace the dropped eggs and maintain the nests. Afterwards, they will guard the eggs for the next four days, and the young ones will eventually hatch.

How Do I Condition My Betta Before Breeding?

It would be best to create a happy and healthy environment for your betta fish before breeding them. With better care, they will lay eggs with a higher chance of getting fertilized. Ideally, feed betta nutrient-rich food like brine shrimp, earthworms, and bloodworms. And when you introduce males to females, use a tank divider to observe their reaction.

How Do I Know if My Betta Mate is Successful?

If the mating is successful, you will see tiny flecks in the bubble nests. These flecks will grow in size over time. Secondly, the males will chase the females away and take care of the eggs.

Can I Feed Betta While Breeding?

It’s not advisable to feed the males during this period. By feeding them, you encourage egg eating.

See also: Top-rated fish food for bettas

Apparently, how to tell if a betta fish is pregnant is easy. Ideally, practice observing all the signs before concluding they are gravid.

Read: How long does swim bladder treatment take to work?


U.S Department of Commerce, National Ocean Service: Do fish sleep?

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