How do guppies reproduce in an aquarium and how often?

Guppies are perhaps the most famous aquarium fish, and for good reason. Their bright colors and lively nature are pleasing to the eye, but the real surprise for many beginners is how incredibly easy they are to breed. Sometimes it seems that they reproduce right before your eyes, without any special conditions on the part of the owner.

The secret to such fertility is that guppies are live-bearing fish. This means that it is not eggs that are born, but fully formed, tiny fry, ready for independent life. Under favorable conditions, this process can be repeated with enviable regularity, and soon a new generation will be frolicking in your aquarium.

But how exactly does this happen? What is needed for the fry to survive and grow? And how often can you expect such fish “replenishment”? Let's take a look at these questions in order so that you can not only observe this miracle of nature, but also help your pets if necessary.

Necessary conditions.

Guppy reproduction is a natural process that does not require much human intervention. However, for best results, there are a few things to consider:

1. The water should have a hardness of no more than 15 units and an acidity of no more than 8.5 pH.
2. The water temperature should be at least 25°C, so the fish will mate more quickly.
3. The maturity of the fish.
4. Use live food that contains protein.

Lighting plays an important role—it illuminates the bright tails of the males to attract females.

Guppies are live-bearing fish.

Guppies are livebearing fish, meaning their young are born fully formed rather than from eggs. Females can give birth to 20 to 60 fry at a time, and under good conditions, every 4–6 weeks. Fertility depends on age, nutrition, and water temperature: the warmer it is, the faster they grow and reproduce. To ensure the survival of the fry, it is necessary to provide hiding places in the aquarium or to remove the pregnant female, otherwise the older fish may eat them.

The onset of sexual maturity.

As mentioned earlier, a necessary condition for reproduction is maturity, the fish's readiness to reproduce. The female reaches sexual maturity when she is 2-5 months old. The timing may be influenced by the environmental conditions in which the guppy lives:

• sufficient lighting.
• high-quality food.

How guppies mate

You will immediately notice when the fish enter their mating season. During this period, they move faster than usual. Males actively pursue females and position themselves alongside or below them. It is important to note that there should be fewer males than females, otherwise the males may chase the females to death. That is, there should be at least two females for every male.

How fish reproduce: Guppies mate using the male's mobile anal fin, which is shaped like a tube and is called a “gonopodium.” Fertilization occurs in the female's abdominal cavity, where the seminal fluid enters. It is then stored in the mother's body for a long time, so the female can be fertilized several more times without the presence of a male.

Avoiding cannibalism

Unlike other fish, these aquarium fish do not have a maternal instinct. Guppies are cannibalistic fish, so after giving birth, the female may eat her offspring. To avoid this situation, it is worth separating the fry from the mother after giving birth if spawning took place in a separate container. Special internal spawning tanks are available for aquariums. If spawning took place in an aquarium with other fish, the fry should be provided with places where they can hide from larger individuals: add various algae, driftwood, and stones to the aquarium.

With good and sufficient nutrition, guppies can be completely weaned off cannibalism.

Fish reach sexual maturity at 4-5 months of age.

Pregnancy period

Since guppies are live-bearing aquarium fish, their embryos develop inside the mother. The gestation period is 20-45 days, most often lasting a month. The duration of guppy pregnancy depends on external factors such as water, nutrition, water temperature, as well as internal factors such as the age of the female. Young fish have a longer gestation period than older fish.

Water temperature has a significant impact: the higher it is, the faster guppies will give birth. However, if the temperature is too high, there is a high risk of premature birth, and if it is too low, the fry will be underdeveloped. During pregnancy, it is important to maintain a stable environment and not change the water in large quantities, as this can cause stress to the pregnant fish, which in turn can lead to miscarriage.

Determining pregnancy in guppies

A pregnant guppy can be distinguished from others by several signs:

• Behavior. She becomes aggressive towards other fish, does not allow males to approach her, begins to eat more, tries to hide, and seeks solitude.
• Appearance. Her abdomen becomes larger and rounder, and closer to giving birth, it becomes rectangular with a black spot visible at the bottom. Her back curves, and her head appears small next to her abdomen; this sharp difference is called a “step.”

In the early stages, especially for beginners, it can be difficult to identify a pregnant guppy, but if you carefully monitor the appearance of these signs, you can easily track the course of pregnancy.

Is it necessary to separate the female for birth?

During pregnancy, it is important to catch the moment when it will be necessary to separate the guppy for birth. Once the fish has a prominent black spot and the anal opening increases in size, it is worth moving the female to a separate aquarium or placing her in a breeding box (a special tray placed in the main aquarium). In such conditions, she will not feel stressed by the presence of other inhabitants of the main aquarium.

The same conditions should be created in a separate aquarium. To do this, fill it halfway with water from the main aquarium and fill the other half with fresh water of a similar temperature so that the female does not feel any changes and does not experience stress.

Note! The aquarium should be 10-15 liters, without soil, with a variety of plants. However, a three-liter jar with the same conditions may also be suitable.

Guppy pregnancy lasts from 20 to 45 days.

Behavior before giving birth

Immediately before giving birth, the female's behavior will change. Before giving birth, guppies eat little or refuse food, and often regurgitate their food. They move little, feel cold, and therefore look for a warmer place, often staying near a heater. If the female remains in the community aquarium to give birth, she will hide at the bottom, hiding from other inhabitants, otherwise the males will chase her and push her belly with their heads.

How birth occurs

The owner should know how guppies reproduce at home in order to control the situation. Giving birth begins when the pregnant guppy freezes and her tail starts to tremble, usually at night or in the morning. Since guppies carry their young in their abdomen, during birth they swim out one by one or in small groups and spread out across the aquarium, hiding so they won't be eaten.

Birth lasts from 1 to 12 hours. You can speed up this process by gradually adding fresh water and increasing the water temperature by 2-4 degrees. The male can also contribute to the birth; in extreme cases, he can be placed with the pregnant female, but after the birth begins, he should be removed.

Postpartum behavior of the female

After giving birth, the guppy quickly recovers, her behavior returns to normal: she becomes active, searches for food, and can become pregnant again. After giving birth, she should be immediately moved to a communal aquarium, separated from the young to preserve the offspring. The tank can be divided with a grid with small holes that large individuals cannot swim through, unlike fry. The offspring are born capable of living without their mother, so her presence and attention are not required; all this falls on the shoulders of the owner.

Fry are born completely independent.

Caring for fry

In the early stages of life, it is important not only to protect the fry from being eaten by their mother or other large individuals, but also to provide them with good conditions and high-quality nutrition. This will ensure that you get beautiful and healthy guppy offspring.

It is important to monitor water quality and enrich it with oxygen using an aerator, changing it frequently. Fry need dense vegetation to help them hide from larger fish. Plants such as hornwort, naja, elodea, Java moss, pistia, and riccia are often used.

Important! Fry need a balanced diet, and any small-sized feed is suitable for feeding them.

How many fry can be born

It is impossible to determine the exact number of guppy fry born, as this is influenced by several factors:

• size of the female;
• number of previous births;
• age of the female;
• keeping and feeding conditions.

The older, larger, and more experienced the fish, the more offspring it will be able to produce. The largest recorded number of fry is 180. It is generally impossible to accurately count the offspring due to cannibalism. The first spawning typically produces 15-20 fry.

Sex determination

The sex of the fry can be determined 1-3 months after birth. They acquire distinctive features that make it easy to sort them.

Female guppies develop a characteristic black spot near the anal opening at one month of age. It is worth knowing that it appears unevenly in different individuals, so it is worth observing the fry for up to 1.5 months to be sure. When breeding purebred guppies, females should be placed in a separate aquarium to protect them from active males and preserve the necessary breed characteristics. It is worth keeping them separate until sexual maturity.

Males are characterized by the appearance of a gonopodium, formed from the anal fin. By the time they reach sexual maturity, males are smaller in size and acquire bright colors, unlike females.

The mother must be removed from the breeding tank after giving birth.

The first days of the fry

Fry are born fully formed, with an average length of at least 5 mm. After birth, the fry swim to the surface to take a breath of air, which fills their swim bladder, and then sink to the bottom and hide. The first five days of life require a lot of attention and special conditions. The water temperature should be kept at 28 degrees and after 3 days gradually lowered to 24 degrees. The water should be changed periodically, replacing 30-40% of the total volume.

Please note! During the first week, the aquarium should be lit around the clock to promote rapid growth of the fry. A filter should be installed in the aquarium, and any substrate that will interfere with water purification should be removed.

At first, feeding is carried out throughout the day: the full daily feed ration is divided into 6 meals. After 1-2 weeks, the number of meals should be reduced to 3 times a day.

What to feed fry

Live dust, rotifers, and micro worms are usually used for feeding. You can also feed them boiled, mashed, and diluted chicken yolk. Special feed is produced on a large scale, which is suitable specifically for fry. Starting from the second week of life, they are gradually transferred to adult feed.

Well-balanced, high-quality food will allow the fry to quickly grow to 2 centimeters in length. At this size, they can be transferred to the main aquarium. This will also affect their coloration, making it brighter and more interesting. It is important not to overfeed the fish or pollute the water with food. To avoid this, you can use dry daphnia powder as food, which will remain on the surface of the water and be easily collected by the fish.

Only live food should be used for the first feeding.

How much do fry grow?

Depending on the care, conditions, and feeding, the maturation and development period of the fry will increase or decrease. If all the rules are followed, the fry will grow into large fish in 3-5 months. Then they will be able to reproduce on their own. During sexual maturation, it is important to separate females from males to avoid early pregnancy and subsequent unhealthy offspring.

It is important to consider and monitor the fry, as their growth is individual, and you need to separate the grown individuals from the rest in time to protect them.

Attention! When the fry reaches 1.5-2 centimeters, it can be transplanted and will not be food for large guppies.

Recommendations for proper guppy breeding

Guppies are a suitable breed of fish for beginners, as they do not require special care or conditions. However, in order to breed beautiful and healthy offspring, it is important to know the basic rules of fish reproduction at home. Sometimes there are situations in which guppies do not reproduce or, conversely, reproduce frequently. In such cases, it is important to understand what the problem is and quickly eliminate it in order to resolve the issue. Often, simply observing the behavior of the fish will help the owner understand and solve the problem. Then watching the fish becomes not only a calming but also an educational activity.

For successful reproduction, it is necessary to monitor the cleanliness and quality of the water.

Why guppies do not reproduce

Aquarium guppies are very fertile, so if they do not reproduce within 1-2 months, it is worth considering the reasons for this situation:

1. All fish in the aquarium are of the same sex.
2. The female is pregnant, but does not yet show the first signs, or they are not noticeable to the owner.
3. Guppies reproduce, but are quickly eaten by their mother or other fish.
4. The fish are stressed due to overcrowding and therefore cannot reproduce.
5. The female's body is not ready for fertilization because she is not receiving enough food.
6. The water has not been changed for a long time. There is no increase in water temperature, which could promote reproduction.
7. Overfeeding fish is just as bad as starving them. Obesity of the internal organs prevents reproduction.

How often do guppies give birth?

Guppies give birth once every 2 months. To avoid overpopulation, you can separate the females from the males. However, this may not have any effect, as female guppies can continue to give birth for months without a male. In this case, you can take no action during pregnancy and allow the female to eat the fry.

As you can see, guppy reproduction is a natural and fairly frequent process. Under good conditions in the aquarium, it can occur almost every month.

The main thing for an aquarist is to create a stable environment and remove the female in time or organize safe shelters for the fry. Otherwise, the adult fish will quickly eat them.

If you keep an eye on these things, your aquarium will soon be full of lively and colorful life. Watching the little guppies appear and grow is a real treat.