Male Vs Female Guppies: How To Tell The Difference! (With Photos)

The simplest way to differentiate between male and female guppies is by identifying the gonopodium on the male, a thin fin on the underside, whereas females have a small triangular fin in the same area.

In this article, I will cover several other characteristics to help you accurately identify male and female guppies.


male vs female guppy Gonopodium
Male vs Female Guppy Gonopodium

One clear difference between male and female guppies is the presence of a modified rear fin in males called a gonopodium, which is slender and straight, while female guppies have a triangular rear fin.

This is a distinct difference between the sexes, but you often need to get close to the fish to identify it correctly.

Depending on the guppy, this may be challenging, as some males may retreat into the plant cover at the back of the tank if you get too close.

However, adding a little food to the tank usually lures most guppies out of hiding, making it easier to get a good look at them.

Body Shapes

male vs female guppy body shape comparison
Male Vs Female Guppy Body Shape Comparison

Female guppies have a large, round body shape, while male guppies have a thin, slender body shape, making it easy to distinguish between the two.

This distinction is evident at all ages, allowing you to identify the sex of your guppy once they are 1-2 months old.

Another advantage of this method is that the body shape difference between male and female guppies remains consistent across various strains of guppies.

Additionally, there are distinct differences in the fins and tails of male and female guppies, further aiding in identification.


male vs female guppy fin comparison
Male vs Female Guppy Fin Comparison

Healthy male guppies typically have longer, flowing fins that gracefully move with the water as they swim, while females generally have shorter, sturdier fins that maintain their form while swimming.

Most male guppies also exhibit brighter colors and more vibrant patterns in their fins compared to females of the same strain.

Additionally, female guppies seem to have an extra fin compared to males. This is because males possess a gonopodium, a modified fin used for reproduction, which we’ll discuss further later.


male vs female guppy tail comparison
Male vs Female Guppy Tail Comparison

Male guppies generally have larger tails compared to females, but this can be tricky to notice due to the overall size difference between male and female guppies.

It’s important to remember that the difference in tail size is relative to the body size of the guppy.

A male guppy’s tail typically accounts for about one-third of his entire length, whereas a female guppy’s tail tends to make up roughly one-quarter of her total length.

Beginners might find it challenging to distinguish between the tail sizes, but as your experience with guppies grows, you’ll be able to quickly identify a guppy’s sex based on its tail.


male vs female guppy size comparison
Male Vs Female Guppy Size Comparison

One of the quickest ways to differentiate between male and female guppies is by their size.

Males typically measure 0.6-1.4 inches (1.5-3.5 cm), while females are larger, ranging from 1.2-2.4 inches (3-6 cm).

This method is convenient and can often be done at a glance, making it my preferred approach for an initial assessment of a guppy’s sex.

However, this method has a potential drawback: younger female guppies can be similar in size to adult males. To avoid confusion, it’s best to use additional identifying characteristics, which are covered in this article, to confirm the guppy’s sex.

For those interested in breeding guppies, it’s worth noting that females often prefer larger males. Therefore, focusing on male guppies around 1.4 inches (3.5 cm) might improve your breeding success.

Colors And Patterns

male vs female guppy color comparison
Male vs Female Guppy Color Comparison

Male guppies are generally more vibrant and colorful than females, making it easy to distinguish between them.

My own male guppies showcase bright hues from head to tail, whereas female guppies tend to have paler heads and bodies, with most of their color concentrated in their tails and fins.

However, some strains of guppies, such as snow white guppies, have males and females with the same coloration, making it more challenging to differentiate between the sexes.

Overall, female guppies are typically less colorful than males, making this a reliable method for identifying their sex in most cases.

Gravid Spot

male vs female guppy Gravid Spot
Male vs Female Guppy Gravid Spot

Female guppies have a gravid spot that becomes darker and more noticeable when they are pregnant.

However, this method has several flaws and serves more as a difference between males and females rather than a reliable way to distinguish them.

For instance, some guppy strains have patterns that may resemble a gravid spot, even in males. Conversely, strains like blonde guppies may have a gravid spot that closely matches their body color, making it hard to detect.

Additionally, gravid spots are typically easier to see only when the female is already pregnant, often rendering this method less useful for initially determining the sex of your guppy.

Final Thoughts

There are several physical difference that make male and female guppies stand out from each other.

Male guppies are generally smaller, have brighter colors, elongated fins, and possess a unique fin called the gonopodium.

Meanwhile, female guppies are larger, less colorful, and have rounder body shapes.

By understanding these characteristics, enthusiasts can easily identify and potentially breed these vibrant fish.