How To Tell if Guppies Are Pregnant?

Guppies are some of the most common fish in the aquarium hobby. Aside from their beautiful colors, they are also very easy to keep. They can cope well in community tanks because of their peaceful and non-aggressive nature.

Pregant guppy in labor

How do guppies give birth?

Guppies are one of the few species of aquarium fish that get pregnant. They are livebearers. Pregnancy is done through internal fertilization.

Unlike most other species of pet fish that undergo external fertilization whereby the females lay eggs for the male to fertilize, guppies, on the other hand, mate with females and fertilize their eggs internally.

The pregnancy cycle of guppies takes about four weeks, and they often lay many eggs. It is the joy of many aquarists to know when their guppies are pregnant. This awareness will help them carry out necessary preparations for the coming fry. They will also be able to give essential care and attention to the pregnant guppy.

Identifying Pregnant Guppies

There are a lot of signs that can help you tell if your guppies are pregnant or not. The symptoms range from a specific change in their physical appearance to a slight change in their behaviors.

One of the significant indications that can help you tell if your guppies are pregnant is the emanation of a belly bulge. Once your female guppy is pregnant, the body parts, especially the belly, will become inflated.

However, you cannot judge the belly bulge at just one instance because the guppy’s stomach can get big for some other reasons, especially if they just finished eating. Therefore, it is important to keep watching if the belly gets more prominent over time.

Another way you can tell if guppies are pregnant is a change in the color of their gravid spot. The gravid spot of pregnant fish often gets darker. This particular sign usually takes a few weeks before it becomes visible.

Dark gravid spot

It is, however, one of the confirmatory signs that can help you tell if your guppies are pregnant. You might also notice some dots around the gravid region that is commonly regarded as the eyes of baby guppies.

Also, body contractions are another indication that your fish is pregnant. This sign is quite vital because it will tell you that your guppy is close to labor. These contractions will make it visible that your guppies are tightening their muscles.

Aside from the physical features, some behavioral signs can also help you tell if your guppies are pregnant. Mating is one of the behavioral indications that show when guppies are pregnant. Coupling is characterized by the male guppies chasing females around. This period of mating also highlights when the injection of the male sperm fertilizes the eggs in the females takes place.

Other than those listed above, other signs can also help you tell when your guppy is pregnant. These signs include;

  • Loss of appetite in the pregnant guppy
  • Shaking, shivering, and restlessness in the pregnant guppy
  • Resting in the base of a tank, and fewer activities.
  • They rub their body on the wall of the tank, leaves, and other surfaces.


It is not very difficult to identify when guppies are in their breeding period. Some apparent signs can help you tell if your guppies are pregnant easily. These signs range from a change in physical appearance to some behavioral changes. It is of paramount importance for aquarists to recognize when their guppies are pregnant to help them make environmental conditions suitable for the guppies.

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