How Guppies Mate: Breeding Behavior & Ideal Conditions

How do guppies mate? It’s a lot faster and more complex than you might think.

Updated August 28, 2023
Guppy Multi Colored Fish in a Tropical Aquarium

Guppies are livebearers, which means that their babies are born live rather than from eggs like most other types of fish, including goldfish. Guppies breed very freely, so you could you can quickly go from a pair to dozens of pet guppies if you choose to keep males and females together. Understanding how guppies mate can help you figure out if your guppies are engaging in breeding and even allow you to predict when you'll get to meet the cute little fry. 

Guppy Fish Breeding Process

The breeding process is fairly straightforward and lightning quick. When conditions are right, a male guppy will try to approach a female with the goal of inseminating her. The female rarely remains still for this activity. She typically darts away, and a chase follows. When the male gets close enough, he extends his gonopodium toward the female's anal vent.

The gonopodium is actually the male's anal fin. It's located just behind his ventral fins and is shaped like a rod and slightly pointed. The gonopodium contains a tube that actually delivers packets of sperm to the female.

Guppy mating takes less than a second. When it occurs, it looks like the male is tapping the female at her vent where her gravid spot is located. This is the dark spot just behind the female's abdomen.

Fast Fact

Even though the guppy mating is extremely quick, the male will usually breed several times to ensure the female has been fertilized.

Guppy Gestation

The gestation period for a guppy varies a bit, and how long she remains pregnant depends a lot on her environment. The average length of the pregnancy is between 22 and 28 days.

Pregnant female Guppy

However, a female can remain pregnant even longer if her water is too cold, because it can slow the development of the babies, also known as fry. She may also delay delivery if there are too many fish in her tank harassing her.

Many Fry From One Mating

It's an interesting fact that a female can go through multiple pregnancies from just a single breeding. Guppies have the ability to store extra sperm packets from the male, so it's possible for a female to give birth about once a month for several months after the birth of the first set of fry.

Fast Fact

Baby guppies are called fry, and each delivery is known as a drop

Ideal Conditions for Guppy Breeding

There's not too much you need to do if you want to encourage your guppies to breed. Just provide the following ideal conditions, and you'll have baby fry in no time.

  • Guppies are tropical fish, and they do best in temperatures between 75° and 85°F (23° to 29°C). Aim for a constant water temperature of 80°F (26.7°C), and this will help inspire your pets to breed.
  • Guppies like hard water, so maintain a pH between 7.0 and 7.6.
  • Offer your guppies some fresh or frozen brine shrimp in addition to their regular flake diet. Feed your fish twice a day and monitor how much food they eat. You should never offer more than they can eat in five minutes.

After Mating, It’s Time to Prepare for Fry

Now that you understand exactly how guppies breed, it's easy to notice when it happens. If your female's gravid spot begins to enlarge and she looks heavier than ever, you can be certain she is pregnant. Make sure you provide her with everything she needs to support her pregnancy, as well as a safe place to have her fry, or she and her tank mates may eat them.

How Guppies Mate: Breeding Behavior & Ideal Conditions