How to Tell if a Guppy Is Male or Female?

The colorful, vibrant young Guppy, a pleasant and beautiful addition to every freshwater tank, is easy to become fascinated by.

Guppies give birth to live offspring and breed quickly and easily, yet they will consume their young if given the opportunity.

Once a male or female Guppy reaches maturity, distinguishing between the sexes is relatively simple.

Male and female Guppies have significantly different appearances, making them easy to differentiate from each other.

Male and female Guppies have different attributes, making them more likely to differentiate from each other.

It’s extremely difficult to tell whether a Guppy or a Livebearer fry is male or female. The latest you can tell is one week after they’ve been born when they’ve reached maturity.

The female Guppy’s gravid spot would have developed after one week. If you’re having difficulties finding it, consider using a magnifier and a flashlight.

Differentiating Between Male and Female Guppies

When it comes to determining the sex of your Guppies, there are three primary differentiating factors. They are as follows:

  • Bodily Attributes
  • Differences in Fin
  • Differences in Growth and Size

You can tell the male and female Guppies apart by looking at the following characteristics.

Bodily Attributes of Male and Female Guppy

Physical attributes are one of the things to look for when trying to identify whether a guppy is a male or a female

Body Form

Male Guppies have incredibly thin, long bodies, whereas female Guppies are often rounder and more significant than male Guppies, measuring up to twice as much as a male Guppy.

Body Dimensions

Female Guppies can reach a height of 2 1/8 inches (6 cm) and are typically larger than male Guppies.

On the other hand, male Guppies can reach a height of 1-18 inches (3 cm).

Color and Patterns

Male Guppies are usually more attractive than their female counterparts, and their bodies are often covered in vivid shading and patterns.

Male guppies may have spots and stripes in orange, blue, violet, green, dark, and white on their bodies and tails.

This shading is used to attract a female mate.

Gravid Spot

The gravid spot is a black area underneath your Guppy’s body, near the tail, which is a definite indication that your Guppy is female.

A gravid spot does not exist in males.

If it’s a female Guppy fry, look for a black region near the belly and anal fin, and you’ll be able to locate the gravid spot.


Although both sexual forms of Guppies have anal fins, male Guppies have a gonopodium, the regenerative organ used to fertilize the female.

Fertilization occurs inside the female’s body in live-bearing fish like Guppies.

Eggs are also produced inside the body, allowing the female to give birth to live fry.

Differences In Fins in Male and Female Guppy

Below are some of the differences between the fins of male and female guppies.

Fins’ Shape

Fins are the parts of a fish’s body that help it swim and gear its motions.

You may also detect a Guppy’s gender by looking at its fin morphology, as male fins are more prominent than female fins.

Dorsal Fin

The dorsal fin is located on the fish’s highest point, approximately 2-3 inches above the fish’s head.

Guppies with males feature larger dorsal fins which flow in the water when they move.

The dorsal fins of female Guppies are shorter and do not hang in the water while they swim.

Caudal Fin

The caudal or tail balance of a Guppy can help you determine the Guppy’s sex.

Male Guppies have large, lengthy caudal fins with elaborating motifs that are frequently vividly colored.

Female Guppies have smaller caudal fins that aren’t as wide or long as males.

Anal Fin    

The anal fin of the Guppy is located beneath the fish and is the smaller balance a little before the tail’s blade.

An anal fin on a male Guppy will be long and stiff, with a somewhat pointed end. To transmit sperm into the female, he will use his anal fin.

Growth Rate in Guppies

You may notice that some Guppy fry develops at a faster rate than others.

Different components recognizing sex distinctions can explain differential rates of growth.

Female Guppies can grow faster than male Guppies, and even among male Guppies.

Guppy fry will grow quickly as they obtain more access to food.

Differentiating Between Male/Female Wild and Fancy Guppies

Wild make and female guppies can be recognized with their physical appearance, while gender differences in fancy guppies can be identified by observing their behavior in the tank.

Differentiating Factor For Wild Guppies: Physical Appearance

Surprisingly, there is a stark difference in the appearance of wild and fancy Guppies.

Wild Guppies are actually less dull and smaller looking.

You can identify a wild female Guppy from her typical gray or beige color and almost transparent fins.

Male wild Guppies, on the other hand, usually have colorful spots or patterns on them, and they are particularly more vibrant looking than their female species.

Differentiating Factor For Fancy Guppies: Behavior in Tank

Besides their physical attributes, you may also be able to differentiate a fancy female Guppy from a male one based on their behavior in the tank.

Typically, both male and female Guppy fish live calmly and peacefully in their own tank or aquarium.

However, when placed together, they can raise quite a havoc for their owners.

Suppose you put a bunch of male and female Guppy fish together in a tank; given that they are at their breeding stage, it can get quite difficult to maintain the peace inside the tank.

Male Guppy fish tend to get too persistent around their female counterparts, and it may be impossible to control them.

Therefore, to save your poor female Guppy from the constant pestering by male Guppy fish, it is better to place them in separate tanks.

If you notice a bunch of Guppy fish following another Guppy in the tank, you can easily tell who is male and who is female.

Frequently Asked Questions about Male & Female Guppies

Below are some of the common questions aquarium enthusiasts have about guppies.

How can I tell whether my Guppies are old enough to breed?

When male Guppies reach sexual maturity, they will also pursue female guppies to copy them, indicating that they are ready to reproduce.

Can you recognize the difference between male and female infant Guppies?

Guppies are small fish that aren’t difficult to reproduce because they do most of the work alone.

The genders of fry can be difficult to determine while trying to decide on sexual orientation or gender identity for rearing choice because they’re so small and still not fully formed.

Sexing baby Guppies takes some time and effort right from the start.

Is it true that a female Guppy fry develops bigger and faster than male Guppy fry?

Sometimes Guppy fry grows more rapidly than others, as you may have seen. Varying growth rates can be attributed to a variety of reasons, including gender disparities.

Female Guppies can grow faster than male Guppies; even male Guppies Guppy fry with more food has a quicker growth rate.

Because larger Guppy fry will have a greater chance of competing for feed than smaller ones, it makes more sense to segregate them by size as well, in order to boost the growth rate of smaller fry, which can only happen if there is less competition for food.

The Bottom Line

We hope you enjoyed reading this guide on ‘How to tell if a Guppy is male or female.’

So, whether you’re raising a Guppy fry for profit or as a pleasant hobby, knowing the sex of Guppy fry is the most crucial aspect because then you can divide them by sex.

This will not only help them become faster but also help control their population.

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