Identifying Between a Male and Female Guppy Fish

To tell between the sexes of a male or female Guppy fish apart is actually very easy once the fish reaches adolescence. In some fishes, the differences between males and females are quite subtle, but the male and female Guppies have very different appearances, making them easy to distinguish from each other.

It’s nearly impossible to tell the sex of a Guppy or any Livebearer fry. Earliest you can tell is one week after they’re born once they have reach adolescence stage. After one week, the female Guppy would have developed their gravid spot. Try using a magnifying glass and a flashlight if you have trouble looking for it.

Here’s How to Tell the Differences between a Male or Female Guppy Fish:

Body and Shape — Female body is a lot rounder and bigger than a male’s. Male Guppies usually have very slender body. Female Guppies are almost twice as big as male are. Males can grow up to 1-1/8 inches (3 cm), females can grow up to 2-1/8 inches (6 cm) when they’re fully grown. The difference in size between a male and female Guppy is very apparent early on.

Colors — Male Guppies are much more colorful than females are since they use their vivid color to attract a mate. Female’s body is usually pale gray or silver bodies whereas a male’s body are colorful with different patterns. Some females do have a bit more color, however if you compare the males and female Guppies from the same spawn, you’ll realize how much more colorful the males are.

Tails — Males have big and colorful tails.

Anal Fin — The male’s anal fin differs in shape. A male’s anal fin is usually long and pointed. Female’s anal fin is triangular shape. The anal fin is the fin just below a Guppy’s tail fin.

Since Guppies breeds fairly easily and frequently, a lot of Guppy owners separates their male and female Guppy tanks to avoid ending up with multiple tanks. It’s not necessary to separate them until the male’s anal fin begins to look pointed since the male Guppies cannot inseminate until its gonopodium is developed.

Read our Breeding Guppies and Livebearers guide to learn more about how to breed Guppies and learn how to take care of their fry.