How to Tell Male From Female Guppies

Guppies are a common beginner freshwater fish. They are colorful, small, and relatively easy to care for. Guppies are social fish, and are often bought or housed in groups. Because of this, it can be important to determine the genders of your guppies in order to anticipate breeding. It can also be fascinating to study the gender differences in your guppies simply so that you can learn more about your pet. There are several ways female and male guppies differ, which you can use to determine gender.

Things You'll Need

  • Fish food
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Instructions

    • 1

      Look at the color of the guppy. Male guppies tend to have much brighter, more vibrant colors along their bodies and fins. Female guppies often look somewhat drab next to their male counterparts. They often appear brownish or grayish. It is especially easy to see the different coloring between male and female guppies when you observe the guppies in a group. Some female guppies, however, may display some bright colors, so use other gender determining factors if you're still not sure about the gender of your guppy.

    • 2

      Examine the anal, or tail, fin of the guppy. Male guppy tails tend to be full, colorful and somewhat angular. This is especially notable in Fancy guppy varieties. Female guppies have shorter, rounder tail fins.

    • 3

      Observe your guppy's behavior. Male guppies are often much more active than female guppies. They may chase the other fish around the aquarium.

    • 4

      Look for a gravid spot on your guppy. Gravid spots are dark spots located just above the anal fin area. Only female guppies will have a gravid spot.

    • 5

      Look for a gonopodium on your guppy. Gonopodiums are modified anal fins that stick out horizontally under the fish. These special fins are often gray in color. Gonopodiums are used in mating in live-bearer fish species, which guppies are. Only male guppies will have gonopodiums. If you see a gonopodium, you can be almost certain that your guppy is a male.

    • 6

      Feed your guppy. Don't overfeed, as this can cause health problems, but feed enough so that the guppy is full. Then, observe the shape of the guppy. Full guppies expand in different ways. Female guppies develop pot bellies, or belly bulges, when they are full. Male guppies develop bulging chests when they are full. Their little pot chest will appear higher, more towards their heads, than the females pot bellies.