Pregnant Neon Tetra: Things to Know About Fish Reproduction

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Last Updated: June 9, 2023 by Flora Gibbins

No, there is no such thing as a pregnant Neon Tetra. Unlike live-bearing fish such as guppies and mollies, Neon Tetras, like most Tetras, lay eggs. They do not carry their embryos inside their bodies.

In fact, male and female Neon Tetras have similar external appearances and it can be difficult to distinguish between them without close observation or breeding behavior. During breeding, the female Neon Tetra will release her eggs, which are then fertilized by the male. The eggs will hatch and develop outside of the female’s body.

While Neon Tetras do not become pregnant, it’s still important to ensure that they are well-fed and healthy to support successful breeding and the development of healthy eggs and fry.

What You Need to Know

Before a female Neon Tetra lays eggs, the males usually exhibit a variety of courtship behaviors to attract her and encourage her to release her eggs. These behaviors can include chasing, displaying their fins and colors, and nudging the female’s abdomen.

Male Neon Tetras will often engage in a “zigzag” dance, where they swim rapidly from side to side while displaying their fins and bright colors. They may also circle around the female, nudging her gently with their snouts or flaring their fins to impress her.

As the female becomes ready to lay eggs, she may become visibly plumper and her coloring may become more vibrant. The male Neon Tetras may become more persistent in their courtship behavior, continuing to chase and nudge the female in an effort to encourage her to release her eggs.

Once the female lays her eggs, the male Neon Tetras will quickly fertilize them. The eggs are adhesive and will stick to plants or other surfaces in the aquarium. After the eggs are laid, the female neons may lose interest in breeding and the male may stop his courtship behavior.

It’s important to note that breeding Neon Tetras can be challenging and requires specific conditions, including a well-established aquarium, appropriate water parameters, and a balanced diet. Additionally, it’s recommended to separate the adult fish from the eggs and fry, as they may eat them. If you’re interested in breeding any Tetra species, it’s a good idea to do some research and prepare accordingly.

How Do Neon Tetra Reproduce?

Neon Tetras reproduce through external fertilization, where the male fertilizes the female’s eggs after she releases them. Females lay their eggs in clumps near plants or other structures in the aquarium. The eggs typically hatch within 24 to 36 hours, and the fry are initially fed with infusoria or other small foods until they are large enough to consume brine shrimp or other live or frozen foods.

Neon Tetra spawn multiple times a year, every few weeks or every few months.

The Best Way to Know if a Neon Tetra is “Pregnant”, i.e. Sexually Mature

To determine whether or not Neon Tetra is “pregnant” or just fat, you need to look for the following characteristics:

Female Neon Tetras generally reach sexual maturity at around 6 to 8 months of age. There are a few signs that indicate when a female Neon Tetra is ready to lay eggs and has reached sexual maturity:

      • Rounder or Plumper Body: Also known as a “breeding belly,” females may appear slightly rounder or plumper when they are ready to release eggs.
      • Brighter Coloration: Female Neon Tetras may become more vibrant in color when they are ready to lay eggs.
      • Behavior Changes: Females may start to display different behaviors, such as frequent swimming near plants, rocks, or other objects in the aquarium. They may also start to chase and interact with males in the aquarium.
      • Distended Abdomen: A distended abdomen is a sign that a female is carrying eggs.

What Do Neon Tetra Eggs Look Like?

Neon Tetra Eggs

Neon Tetra eggs are tiny, transparent, and almost spherical in shape, measuring only about 1mm in diameter. They are usually adhesive and stick to surfaces such as plant leaves or the aquarium glass. After being fertilized by the male, the eggs will hatch within 24 to 36 hours.

The Neon Tetra fry emerge from the eggs as tiny larvae that are almost translucent, with small yolk sacs attached to their bellies that provide them with nutrients for the first few days. Within a few days, they will absorb the yolk sacs and start swimming and feeding on tiny live foods.

How Long Does it Take for a Neon Tetra to Lay Eggs?

The time it takes for Neon Tetras to lay eggs can vary, but it usually takes several days of breeding activity before the female Neon Tetra is ready to release her eggs.

How Long Does it Take for Neon Tetra Eggs to Hatch?

The Neon Tetra is often seen with the mother and father in the same tank in the wild. Depending on how many male and female parents you have in your tank, you may see the eggs hatch quickly or not at all when they are ready to hatch.

The Neon Tetra species has a very short gestation period, about 14 weeks.

Female Neon Tetras vs Male


Distinguishing between male and female Neon Tetras can be challenging, especially for inexperienced aquarists or with young fish. However, with some practice and close observation, it is possible to identify certain physical characteristics that differentiate the sexes. The differences between males and females can be subtle, and it may require careful examination of the fish’s body shape, coloration, and fin structure to determine its sex.

Female and male Neon Tetras can be distinguished by examining their physical characteristics.

Male Neon Tetras typically have a slimmer body and a more intense coloration than females, especially in the blue and red areas of their body. They also have a straight, thin blue line running along their undersides.

Females, on the other hand, tend to have a larger, more rounded belly and a less intense coloration than males. They have a more pronounced white or silver area on their bellies, and their blue line is curved, following the shape of their belly. Additionally, females may have a small, white spot on their dorsal fin.

Breeding Neon Tetras

The Neon Tetra fish can begin to breed as soon as they reach 4-5 months. They can be bred in an aquarium at least 1 foot wide and 1 foot deep.

The water should be around 2-3 gallons. It is essential to ensure that there are no more than 10-12 Neon Tetras in the breeding tank because more than this will hinder the growth of algae and thus the breeding of the fish.

The male Neon Tetra will build a nest using his fins and body under a plant in an aquarium. The male will then attract the female by dancing with her. This dance involves swimming in front of her and flaring his fins repeatedly. After this, the male will follow her around and nudge her to see if she is ready for mating.

To breed the Neon Tetra, you will need to prepare their bedding. You can collect peat moss or black cotton soil from your lawn and mix it with water in equal quantities.

After allowing the mixture to become watery, pour it into a plant pot with small holes in its bottom.

The plant pot should be placed in a fish tank at least 2 feet wide by 1 foot deep and contains at least 2-3 gallons of water. Ensure that you add some plants like Java Moss or ferns to the breeding tank so that they can camouflage themselves in them.

After this, the male Neon Tetra will be able to choose which plant they want to mate using as a bed. The male Neon Tetra will then get into the water and swim around in front of the female. After this, the female will move to the plant pot and lay her eggs on it.

The Neon Tetras lay up to 200 eggs in 2-3 days, after which she will cover them with her body and go back into the water. The male fish, ready to breed with the female fish, will try his best to get close to her within about 1/4 of an hour. If he is successful, the rest of the eggs will be fertilized and hatch after about a week.

After Neon Tetra eggs hatch, the Neon Tetra will begin their first meal within 15-20 minutes and continue eating for a few hours. However, it would be best if you did not overfeed them as it can affect their growth patterns. The Neon Tetra is omnivorous and can eat both plant matter and meaty foods. They are also known to eat each other if they get too much food.

Breeding Requirements For Neon Tetras

It would be best if you did not overfeed Neon Tetra fish, though you can add some finely crushed flakes to food for them.

The Neon Tetra requires a pH of at least 7.5 in the water for breeding. The average size of their eggs is about 0.4mm or about 0.015 inches.

It is recommended to have 10-12 Neon Tetras per level, 2-2.8 gallons in the breeding tank.

Neon Tetra Aquarium Care

Neon Tetra Aquarium

The Neon Tetras can survive in smaller aquariums and can live in 2-3 gallons of water. It is recommended to have 2-3 Neon Tetras per tank, and they can be kept with other small fish.

The Neon Tetra can survive with a temperature level between 66 and 78 degrees Fahrenheit, a pH value of 6.0 – 7.0, and a 5- to 10-degree range of hardness. The fish require moderate lighting, and bright light intensity is necessary for the fish to grow well in their tank.

The aquarium water temperature must be maintained at 66 to 78 degrees F. The pH level must be maintained between 6.0 and 7.0, with a water hardness of 5 to 10 dH.

These fish can be kept in an aquarium that is 2 feet wide by 1 foot deep, and thus, it will require only 1-2 gallons of water. The fish need to have enough space for swimming and hiding places in the tank to feel safe in the breeding tank.

Fun Fact: We rarely talk about shrimp pregnancy, don’t we? Check out this article, Pregnant Ghost Shrimp: Beginner’s Guide To Proper Breeding, and be informed!

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Frequently Asked Questions

How do I know if my tetra is pregnant?

When a tetra is pregnant it will look like it has developed a potbelly, as well as being noticeably bloated.

Do Neon Tetras breed easily?

Neon Tetras are considered one of the easiest fish to breed in the aquarium hobby. The male and female pair up, and shortly after that, the pregnant Neon Tetras lay eggs on a flat surface (usually plants) for about 2–4 weeks.

How long does a tetra stay pregnant?

The female tetra will lay her eggs after about 14 weeks. Some females can lay their eggs earlier if they are not properly cared for. Pregnancy is usually at the end of 14 weeks. A fully grown pair of these fish can live up to 2-3 years in captivity.


You now have a basic understanding of what it takes to house and raise your Neon Tetras. It is essential to know that these creatures grow very fast, and there is no guarantee of whether they will survive.

However, you also need to realize that the Neon Tetra fry is very tiny, and there are a lot of components that go into their growth. If you’re dedicated and want to raise healthy tetras, then make sure you do your research before adding them into your tank.

As long as you stick to the basics, it’s very likely that your Neon Tetras will be fine and thrive in the aquatic environment.

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