How Often Do Guppies Get Pregnant?

Guppies, like mammals and some other fish, give birth to live fish fry. Among the most popular tropical fish, they are prolific breeders who can get pregnant many times each year. A single male can inseminate multiple females and does so by approaching the female and injecting his sperm with a small reproductive structure called a gonopodium. Guppies frequently eat their babies, so it's important to separate fish fry from adults.

  1. Gestation

    • The gestation period for guppies is 3 to 5 weeks. Guppies can become pregnant again immediately after giving birth, so it's possible for a guppy to give birth every few weeks for most of her life.

    Sperm Storage

    • Like some other fish, female guppies are capable of storing sperm for several months after being inseminated. Consequently, a female who is separated from a male can still become pregnant after giving birth. Guppies can usually re-inseminate themselves with stored sperm three or four times.

    Age

    • There are two important limiting factors to guppy pregnancies. Females are sexually mature around 3 months old and cannot get pregnant before this age. The average guppy lifespan ranges from one to three years. Consequently, a single guppy can give birth dozens of times in her life.

    Environmental Conditions

    • Guppies are more likely to get pregnant when the aquarium temperature ranges from 75 to 80 degrees Fahrenheit. Ambient temperature also affects gestation period. A guppy in warmer water typically gives birth more quickly. Other environmental conditions, including diet, aquarium pH, overall health and tank size can also affect how frequently a guppy gets pregnant and how long she gestates the fry.