For female guppies to be pregnant, they must have spent at least some time with a male guppy, however after the initial fertilization has taken place, the female guppy can store the males’ sperm for future use, meaning she can have babies for several months, even is she subsequently lives without a male guppy.
Guppies have long been one of the most popular breeds of tropical fish in the freshwater fishkeeping hobby. Since the 1960s, hobbyists and professional breeders have been working to develop the hundreds of different colors, patterns, and tail shapes we can all enjoy today.
I first started keeping and breeding guppies in the mid-1990s when I was given a 10-gallon tank and a small group of guppies. Since then, I don’t think a single day has passed when I haven’t had at least one tank full of guppies.
How Can Female Guppies Store Male Guppy Sperm?
According to research by David Reznick, a professor of biology at the University of California, Riverside, female guppies can store the sperm from male guppies in a specially developed cavity in their ovaries. They keep the sperm alive with very small amounts of sugar until they need it to fertilize the eggs. Professor Reznick and his team believe female guppies can store the sperm from a single male for up to 10 months.
How Many Babies Can A Female Guppy Have Without A Male
There is no real limit to the number of babies a female guppy may have after she was last with a male. It would probably depend on how much of his sperm she was storing and how many babies she had in any one brood.
In my experience of breeding guppies, a female can have anywhere from 40 to 100 or more babies in a single brood. In theory, a female guppy could have 8 or 10 broods of babies without a male being present, but the number of babies in each brood would probably go down the more broods she had.
Can Female Guppies Self-Reproduce?
No, female guppies can not self-reproduce. For a female guppy to have babies, she has to have been in the presence of a male guppy for at least a short period of time.
Male guppies are such persistent breeders that the female and male-only have to be in the same tank together for a matter of minutes before there is a good chance a successful mating has occurred.
What Happens If Female Guppy Breeds With A New Male Guppy?
Further research has shown that even if the female is storing sperm from a previous mating, there will be a bias towards the sperm of a new male. This is useful to know if you are trying to breed a female guppy to a particular male for line-breeding reasons.
I have spent a lot of time breeding guppies and trying to improve the coloration of some of my strains. There have been numerous occasions when I have wanted a particular female to mate with a particular male, but I know another male may have mated with her already. Knowing she can store the sperm, I know she may have the genes from a male whose color I don’t want.
To solve the problem I put her in a separate tank with only the male whose color I want to breed into the babies.
Although it may appear that a female guppy is having babies without a male guppy being present, she must at some point have been in the presence of a male guppy. Female guppies have the ability to store the male guppy’s sperm in a special cavity in their ovaries.
They can use this sperm to fertilize future broods of eggs for up to 10 months. Female guppies CAN NOT self-reproduce.