Guppies are some of the most popular freshwater fish for home aquariums. If you’re a guppy owner, you’ve probably noticed some interesting mating behaviors. Read on to learn everything you need to know about guppies mating and reproducing.

If you’re short on time, here’s the key point about guppies mating: Male guppies pursue and mate with female guppies through a courtship display. Females can store sperm and give birth to multiple broods from one mating.

In this comprehensive guide, we’ll cover how guppies select mates, their mating ritual, gestation period, brood size, and more. You’ll learn fascinating facts about these lively fish that make them a favorite for aquarists.

Courtship Displays

When it comes to guppy courtship and mating rituals, the males go to great lengths to attract the females. The males perform intricate and colorful displays, hoping to catch the eye of females ready to mate. The receptive females then choose the most appealing male to reproduce with.

How Males Attract Females

Male guppies have evolved vividly colored scales and large, showy fins to grab the females’ attention. Studies show that female guppies prefer males with more color saturation, especially orange, black, and iridescent spots. The bolder the colors, the better chance a male has at reproducing.

In their courtship dance, male guppies also exhibit behavioral displays like the “sigma” dance and “sneaky mating.” In the fast-paced sigma dance, the male guppy rapidly oscillates his body in an S-shaped, zig-zag pattern to demonstrate his fitness and health.

Males will often trail females for hours, even days, waiting for an opportunity to mate. This strategy is called “sneaky mating” and allows the males to reproduce without having to out-compete other males through flashy displays.

Female Choice

Female guppies are selective when picking mates. According to studies, females evaluate multiple factors when choosing a male, including:

  • The size and symmetry of colorful spots
  • The area of iridescent and orange coloration
  • The number and surface area of the male’s fins

In one experiment, when given a choice, female guppies preferred males with larger, more intense orange patches and bigger dorsal fins. The choosy females know that healthy, attractive males will likely produce fitter offspring.

However, females must also evaluate risk. The flashiest, most vigorous males often attract more predators too. So females will sometimes mate with the less colorful males if they offer an optimal blend of good genes and predator avoidance.

The Mating Process

Sperm Storage

Female guppies have the amazing ability to store sperm inside their bodies after mating. This allows them to fertilize multiple broods of offspring over an extended period without having to mate again. Here’s how it works:

  • During mating, the male guppy transfers sperm packets called spermatophores to the female. These spermatophores can contain up to 40,000 sperm cells each!
  • Special sperm storage structures called sperm storage tubules allow the female to retain these spermatophores in her ovary and oviduct for up to 5 months.
  • When the female is ready to produce a brood, she can selectively draw from this sperm reserve to fertilize her eggs.
  • This gives her control over precisely when and how many offspring to produce at a time.

Sperm storage provides major advantages for guppy reproduction and survival. Females don’t have to waste energy finding a mate before each brood. They can also continue reproducing for some time if males are scarce.

And if environmental conditions turn bad, they preserve the option to wait it out before producing more offspring. Truly an ingenious reproductive adaptation!

Multiple Broods

Thanks to sperm storage, female guppies can give birth to multiple broods over their lifetime. Here are some key facts about their remarkable ability to produce successive broods:

  • Guppies are ovoviviparous, meaning females give birth to live young rather than laying eggs.
  • Gestation takes 21-30 days, after which females give birth to anywhere from 1-100 fry per brood.
  • Females can produce a new brood every 28-37 days by drawing on stored sperm.
  • In ideal conditions, each female can bear 3-12 broods per year.
  • Lifetime brood production averages 150-300 offspring, but can reach up to 800!

Multiple brooding allows guppies to exponentially multiply their numbers in a short time. It’s one reason they thrive in the wild and in home aquariums. However, producing many broods does tax the female’s body.

So while possible, reaching the upper limits of reproductive output requires excellent conditions and genetics.

Gestation Period

The gestation period for guppies can vary slightly depending on factors like water temperature, but is typically around 21-30 days. Here’s an overview of what to expect during this important developmental stage:


Once mating has occurred, the male guppy deposits sperm into the female’s oviduct where her eggs are stored. The sperm then swim to the eggs and fertilization takes place internally within the female. Each mating can result in 20-60 fertilized eggs.

Early Development

The fertilized eggs remain protected in the female’s oviduct as they divide and develop. After about 10 days, the eyes of the developing embryos become visible through the translucent egg shells, indicating they are nearing full development.


About 21-30 days after mating, the female guppy undergoes the birthing process. This involves her arching her back and rapidly contracting her abdominal muscles to push the developed fry out of her oviduct.

The fry emerge one by one over a period of 6-12 hours, often totaling 20-60 offspring from a single gestation period.

The newborn fry are already fully developed and ready to swim and feed independently. They do not receive any parental care. Within just a few months they reach sexual maturity and the reproductive cycle begins again.

Influencing Factors

While 21-30 days is the typical gestation period, the exact length can vary based on factors like:

  • Water temperature – Warmer temperatures speed up gestation.
  • Female’s age – Younger females tend to have shorter gestation periods.
  • Brood size – Larger broods take slightly longer.
  • Genetics – Some strains have naturally shorter or longer gestation periods.

By closely monitoring water parameters and the female’s development, guppy breeders can approximate when to expect the birth, though the exact timing can be difficult to predict.

Brood Size

Guppies are prolific livebearers, meaning they give birth to live young instead of laying eggs. The brood size of guppies can vary greatly depending on several factors.

Number of Fry

On average, female guppies give birth to 20-60 fry per brood. However, brood sizes can range from as few as 1-2 fry up to 100 or more! The number of babies born depends on factors like:

  • The age and size of the female – Older, larger females tend to have more babies per brood.
  • Genetics – Some strains of guppies are genetically predisposed to having larger broods.
  • Environmental conditions – Ideal water parameters and abundant food sources enable females to produce more offspring.

Frequency of Broods

In addition to brood size, the frequency at which female guppies give birth also affects total fry production. Given optimal conditions, females can produce a new brood of fry every 20-40 days. That means one female could give birth 12+ times in a year!

By allowing females to produce multiple, large broods in quick succession, guppies are able to multiply rapidly. In fact, a single female guppy and her offspring can theoretically produce over 200,000 fry in one year!

Growth Rate of Fry

Guppy fry grow quickly in their first few months, reaching sexual maturity in as little as 2-3 months. The rapid maturation allows them to start reproducing at a young age, further compounding population growth.

With such high reproductive output, it’s no wonder that guppies are one of the most ubiquitous aquarium fish around. Given adequate space and resources, guppy numbers can exponentially increase in no time at all!

Raising Fry

Separating Males and Females

When raising guppy fry, it is crucial to separate the male and female fish once the fry are born. Allowing mature males to remain with the females and fry can lead to the aggressive males harassing the females and even eating the fry. Here are some tips for safely separating the sexes:

  • Use a breeding trap or partition to isolate the pregnant female before she gives birth. This prevents the male from immediately attacking the fry.
  • Once the fry are born, move the female along with the babies into a separate nursery tank. Make sure the nursery tank is cycled and maintained with optimal water parameters.
  • Only keep female guppies together with the fry. Female guppies are less likely to cannibalize their young.
  • Wait until the fry are around 12 weeks old before introducing any mature males back into the tank. By this age, the juvenile fish are big enough to not be seen as prey.

Segregating the sexes ensures the vulnerable fry have time to safely grow and develop. When they reach adulthood, the males and females can once again cohabitate in a community tank.

Feeding Fry

Proper nutrition is vital for growing guppy fry. While adult guppies can thrive on flake foods, the fry require specialized diets to support their rapid development in the first few months of life. Here are some feeding tips for guppy fry:

  • For the first week, feed newly hatched brine shrimp or microworms 2-3 times a day. These tiny, protein-rich livestock are easy for fry to consume.
  • Around 2 weeks, introduce powdered fry food or crushed up flakes. Feed 3-4 times daily.
  • At one month, offer micro pellets formulated for fry several times a day along with continued feedings of brine shrimp or microworms.
  • By 6-8 weeks, transition to feeding small pellets 2-3 times daily. Supplement with frozen foods like daphnia or baby brine shrimp for variety.

Only feed what the fry will consume in a few minutes, and siphon any uneaten food from the tank bottom to prevent fouling the water. Perform regular partial water changes and test water parameters frequently.

With a proper diet and good water quality, guppy fry will grow quickly and display bright, vibrant colors.


Guppies have unique reproductive habits that make them endlessly entertaining aquarium fish. Their courtship displays, internal fertilization, and ability to store sperm and deliver multiple broods are fascinating to observe.

By understanding the guppy mating process, you can better care for your fish and enjoy watching new fry develop.

With this guide, you now have in-depth knowledge on all aspects of guppies mating and reproducing. You’ll recognize their mating behaviors and know what to expect as your female guppies deliver new broods. Use these tips to successfully raise healthy, thriving guppies.

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