How to Tell if a Neon Tetra Is Going to Lay Eggs?

If you are trying to breed neon tetras, you’ll need to be able to tell if they are going to lay their eggs. 

This is an important stage in the breeding process, so you should educate yourself. The mating process of these fish is fairly complex, which is why it’s crucial to learn all you can.

Identifying a Neon Tetra that is About to Lay Eggs

1. Males vs. Females

There aren’t a lot of dramatic differences with regards to the physical appearance of male and female neon tetras. Females do tend to be a bit bulkier than males. 

The blue coloration on females is curved, whereas males have a straight neon bar going across their body. It is much easier to make this distinction when you only have a male and female in the tank. This is the recommended setup for breeding.

2. It’s All About the Belly

You can usually tell when a female tetra is about to lay eggs by their protruding belly. They will be larger around than the other females in the tank. This is a strong indication that the egg laying process is imminent.

These fish rarely become obese, unless they are seriously ill. This means that you won’t have to worry about distinguishing between a pregnant female and one that is just fat.

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neon tetra white stones

3. Pre-Mating Behavior

When a male neon tetra wants to attract a female for mating purposes, they will do a sort of dance around them. You will notice the male swimming around in sharp 90 degree angles. The male might take the occasional break, not moving much but still keeping a close eye on the female they are trying to woo.

How Long Does the Egg Laying Process Take?

The average neon tetra produces anywhere from 60 to 120 eggs when giving birth. These eggs are fertilized by the male right away. Unfortunately, there will inevitably be some eggs that don’t end up hatching. This whole process can last up to 24 hours. You will notice tiny tetras emerging from their eggs throughout this period of time.

When the fish come out of their eggs, they look more like tiny shimmering specs than anything else. You’ll need to take the parents out of the tank immediately, as they will eat their offspring otherwise.

Basic Requirements for Breeding Neon Tetras

There are a number of basic requirements that you will have to satisfy in order to breed neon tetras. It is important that you go through this list before getting started. The more you know prior to attempting to breed these fish, the better your chances will be.

neon tetras in an aquarium

1. Get a Separate Tank for Breeding

The first thing you will need to do is to get a tank that is dedicated specifically for breeding your neon tetras. This tank should be at least 20 to 30 gallons. There should be enough space for the adult fish, as well as the offspring when the eggs start hatching. 

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You’ll also want to make a point of keeping the lid securely on top of the tank. This will keep the adults from jumping out, which could be a complete disaster. 

Avoid buying a used aquarium, as it might contain certain contaminants that can make breeding these fish considerably more difficult. The last thing you want is for any baby fish to be born into a contaminated environment.

2. Finding the Right Place for the Tank

Once you have your tank, you will need to find a good place to put it. You should try to find a fairly dark area, as you don’t want any direct sunlight shining down on the tank. These fish only need a tiny amount of light on a daily basis, so you’ll want to keep that in mind.

3. Water Conditions

The water in your breeding tank should be kept within a pH range of 5 to 6 at all times. You’ll also need to make sure that the temperature stays around 74 degrees Fahrenheit. If the temperature goes below 70 degrees, your fish could be in serious trouble.

It is recommended that you replace half the water in the tank on a fairly regular basis. This will go a long way towards getting your fish to mate. When the water is clean, fish are simply more likely to breed.

Use a high quality box filter to keep the water in the tank as clean as possible at all times. This filter will prevent potentially dangerous bacteria from accumulating. This is definitely not something that you will want to go cheap on.

You’ll need to carefully monitor the various water conditions every single day to ensure that they are ideal. It is especially important to keep track of the water softness, as this plays a crucial role in stimulating the breeding process.

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After the Eggs Hatch

Once the eggs have hatched and the baby tetras are born, you’ll want to eliminate any nearby light sources. It is important that they stay in the dark, at least for a while.

You’ll want to have fish food that is specifically formulated for baby neon tetras at the ready. Once the fish are a few days old, they can start eating juvenile brine shrimp.


  • The easiest way to tell the difference between male and female tetras is by examining the horizontal blue stripe on the side of their body. Females have a curvy stripe, whereas the males are straight.
  • A neon tetra that is about to lay eggs will almost always have a distended belly that becomes more noticeable the farther along they are.
  • You can tell when the mating process begins by observing the “dance” that the male does for the female.
  • These fish can lay up to 120 eggs within a 24 hour period.
  • If you want to breed neon tetras, you will need to have a separate tank that is at least 20 gallons.
  • Make sure that you place the breeding tank in a dark place away from direct light.
  • Carefully monitor the pH, temperature, and softness of the water in the breeding tank on a daily basis.
  • Once the eggs hatch, take the parents out so they don’t eat their offspring.
  • You can feed the offspring special fish food that is specifically meant for baby neon tetras.

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