Selective Guppy Breeding: The Ultimate Guide

Guppies give birth more than you can ever expect. You do not need to purchase lots of guppies since your 2 or 3 guppies would reproduce continuously and you will end up with a tank filled with tens and dozens of guppies.

Guppies are one of the most beautiful tropical fish that are famous for their colors that are attractive to everyone’s eyes. Fish hobbyists never seem to get bored of this species no matter how many times they breed guppies.

Selective Breeding Guppies (Video)

Guppies are hardy in each and every way, even when it comes to their price; it is quite reasonable and affordable. Guppies are famous among children, in particular. Imagine how easy it is to keep guppies that even a kid could take care of them. This signifies that the fish is pretty interesting and keeping it as a pet is not something that would exhaust you or disturb you.

Even though people are trying to control the guppy population to avoid having an overcrowded tank filled with guppies that are angry at being stuck in such a very small space where they cannot swim freely, some people still are curious to know about breeding guppies and what are the requirements to breed this unique species.

Let us now indulge in more details about how to selectively breed guppies. But before we do that, we need to understand the process of breeding itself.


Guppies belong to the family of live-bearing fish; meaning that they give birth to live babies instead of laying eggs.

When you provide your guppies with good tank conditions, you will guarantee that your guppies will be healthy, energetic, and have proper spawning.

Guppies do not even need your interference to breed. They do that on their own without facing any trouble. Even if the tank is overcrowded, they would still mate and give birth. That is why you have to take into consideration purchasing a big tank to give enough room for every guppy to swim freely.

Plus, if you plan to breed guppies, you must purchase an excellent filtration system. Yes, we said before that guppies do not necessarily need a filter but when it comes to breeding them, you have to provide a pure atmosphere for the fry to grow because any bacteria in the water could kill the fry.

Guppies can function properly and on their own even when they are little fry. The fry depend on themselves completely in everything when it comes to feeding. They are very independent and they go on eating and they grow up fast and reach adulthood.

How does fertilization take place?

The male has an anal fin which is known as the gonopodium. Once this sexual organ develops in the male, you have to know that he is ready to mate and impregnate a female guppy.

The male guppy would start chasing females by wiggling his tail to capture a female’s attention and then mating would start. The male would make a brief contact with the female and use his gonopodium for fertilization.

The sperms are released and transferred to the female through what is known to be her cloaca. The gonopodium is formed by the fusion of the “third, fourth and fifth rays of the anal fin” as explained by scientists and pet fish professionals.

The gonopodium look like little hooks that help the male guppy hold the female during mating. This is the process of impregnating the female guppy. Then, the gestation period remains for about 21 to 30 days. And then the female guppy starts giving birth to her little fry.

The female guppy could give birth to up to 200 fry. It depends on the size of the female and its health as well. It is believed that the larger the female guppy is, the more fry she gives birth too. The average number of baby guppies that a female guppy could give birth to is 20 to 40.

Some of the fry die after their birth and some are born healthy and energetic. There is a very famous guppy in the Chicago Shedd Aquarium which gave birth to 244 fry and 238 of them survived. Isn’t that just something incredibly out of this world!

It is crazy and astonishing how fragile and small creatures are capable of so many great things that leave people in awe!

Selective breeding

In order to do selective breeding, first of all, you have to select certain types of guppies. You must choose guppies that are so distinguished and have superior and desirable characteristics.

For example search for guppies with eye-catching bright colors or guppies that have unique and unusual patterns and tails. Now, after picking the unique male, you have to choose a female that looks like the male although it would be difficult since female guppies are not as colorful as the males.

The more the guppies look unique, the better the new generation will look like. You are going to create new strains and thus, you have to select the guppies that will enhance that strain.

Males are responsible for passing down their genes to the next generations and the mother carries the genes after the mating process. When you bring pure strains to mate, the next generation would also be pure or it could introduce new variations and new characteristics which is also a good thing.

Some mutation could occur and cause the fry to have different traits. Under all circumstances, you will have succeeded to do selective breeding.  You can separate a male and a female in a breeding tank to give chance to the fry to find room to swim in.

The breeding tank needs to have a filter and very clean water. You have to add some floating plants too in order to help the fry hide from the adults. Once the labor is over, remove the mother and the father guppies from the breeding tank because guppies can eat their babies.

Now it is time to draw your attention to the fry and provide them with clean water that is changed regularly to prevent their infection of any disease or bacteria.

Feeding the fry

Feeding is very important to help the fry grow healthy. It is necessary and highly recommended to feed the fry newly hatched brine shrimp to give them power and help them grow faster. Do not forget about adding the floating plants that will help the fry hide behind them while they are feeding until they finally develop into adults. Food also helps in increasing the fry’s body sizes and length. They must be fed about 4 to 5 times a day. But of course you have to feed them small pieces of food and fish flakes. You can feed guppies almost anything. They welcome any variety of food. A mixture of vitamins and proteins helps in making them healthier and helps lengthen their lifespan. Feed them vegetables like chopped peas and lettuce or spinach. Regularly remove any food leftovers because any remains would pollute the water and make it seem murky and unclear. The fry needs clean pure water to grow faster and healthier.


Even though guppies are hardy, pregnant female guppies are prone to chilling and this could cause an infection with ich disease. Therefore, the water’s temperature has to be 78 and 80 degrees Fahrenheit.

Breeding types

There are some types of breeding that you must know about:

  • In-breeding which means first-degree relative guppies mating.
  • Line breeding means mating distant relative guppies or two different lines.
  • Out-crossing is mating two different guppies of the same pure strain.
  • Backcrossing is mating hybrid guppies.

Selecting a healthy guppy

In order to breed guppies, you first have to select a male and a female guppy. But also you have to select healthy and ready-to-reproduce ones. It is not a random process; you have to select healthy guppies that are not infected with bacteria or parasites.

You also have to choose guppies that have become adults and are ready to reproduce. Males become adults on reaching one month of age and females around 2 to 4 months. Male guppies that are ready to mate usually have large tails.

Moreover, you should look at the caudal peduncles for they must be thick. The dorsal and caudal part of the body are supposed to have the same colors and patterns and should be wide too.

While buying guppies, stay away from guppies that have flat heads, poor colors or curved spines. These features indicate that the guppies are unhealthy and are prone to diseases.

Related Questions

What temperature do guppies breed at? Guppies breed at a water temperature that is between 72 and 78 degrees Fahrenheit.

How do you know when a guppy is going to give birth? The female’s gravid spot becomes very dark and big, it hides and freezes in its place a lot and it does not eat properly.


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