Male vs Female Guppies (How to Identify Each By Color, Size, Shape & More)

by Kevin

Male vs female guppies explained.

If you are interested in breeding guppies, or if you already have baby guppies and want to know which ones are males and which are females, then this article is for you.

Telling the Difference Between Adult Male and Female Guppies

Male and female guppies in a planted tank.

Let’s start with the adults.

The main differences between male and female guppies boils down to:

1. Color

2. Size & Fin Shape

3. Behavior

4. Lifespan

5. Tank Mates


Male guppy with a colorful tail (caudal fin).

In general, male guppies, are more colorful and vibrant compared to females.

The most colorful part of a male guppy is his tail (caudal fin), which he uses for displaying to females.

Female guppies are typically more subdued in color, usually a silvery-grey or light brown, and look more like a fish you would find in the wild.

Size & Fin Shape

Illustration comparing male and female guppies.

Adult female guppies tend to be larger than males, with rounder, balloon-like bodies, and shorter tails (caudal fin).

Besides shorter fins, adult female guppies can also be distinguished from males by their gravid spot, which is the womb of a guppy, where the baby guppies develop before being released (remember that guppies are live bearers).

This gravid spot becomes larger and darker when a female guppy is pregnant and is an easy way to tell which guppies are male and which are female.

In general, males guppies have a more streamlined shape, with a fancy, flowy tail fin that is used to impress females.

Male guppies can also be distinguished from females by locating the male’s gonopodium, which is a modified anal fin that the male uses during breeding to transfer sperm into the female guppy (the gonopodium apparently has claws at the tip…).


Male guppies in an aquarium with other fish.

Both male and female guppies are a very peaceful fish, and make great tank mates for a variety of other tropical fish and invertebrates.

But, there are small behavioral differences between the two guppy sexes.

Male guppies are more insistent or nagging than female guppies.

When a female guppy is present, the male guppies will constantly pester her.

Even in a tank consisting of only male guppies, they will chase and sort of peck each other.

I say “peck” because, in my experience, male guppies do not nip or cause fin damage, but rather seem to bump into each other with mouths open.

Female guppies are more docile than males, but will get excited if they think it’s feeding time and push themselves up against the glass, swimming vigorously.

Overall, both males and females are extremely peaceful fish, but females are slightly more peaceful and that might something to take into consideration when setting up a new tank.

Personally, I like keeping a planted 5 gallon tank with a group of male guppies, who keep think lively and full of action.


How long do guppies live and do female guppies live longer than males?

I haven’t observed one living longer than the other and I haven’t seen any research that supports females or males living significantly longer than the other.

But, in general, guppies live between 1-3 years on average, with some individuals living over 5 years.

Guppy lifespan depends on a variety of factors, including genetics, exposure to disease, overfeeding, breeding frequency, and exercise to name a few.

Basically, both male and female appear to live a similar amount of time, but studies have yet to confirm.

Tank Mates

Guppy in a planted tank with cardinal tetras.

Keeping Guppies With Other Fish

The ideal tank mates for guppies are fish like mollies, platies, neon tetras, and other community fish (a term for fish that can live peacefully together).

Avoid keeping guppies with territorial or aggressive fish like cichlids and puffer fish.

I would also avoid keeping guppies with betta fish because bettas sometimes become triggered by the colorful fins of male guppies.

But, the much less colorful female guppies are a decent tank mate for a betta fish, but even then, a betta might try to take a nip at one of the guppies here and there, it depends on the personality of the individual betta.

Keeping Male Guppies Together

Male guppies in a group.

Unlike betta fish, male guppies do well when kept together.

This is ideal because guppies are also known as million fish.

The term “million fish” refers how quickly and readily guppies reproduce.

If you place two males and three female guppies in a tank, it will soon be full of baby guppies because female guppies can produce 50+ babies each month.

If you want to avoid having to re-home hundreds of baby guppies, I recommend having only male guppies in a tank.

For a group of 3-4 males guppies, a 5 gallon aquarium works well, check out my tutorial on setting one up if you want to learn more.

How To Tell Which Baby Guppies are Male and Which are Female

Male vs female baby guppies.

Identifying which guppy fry are male and which are female is impossible until the fish grow older.

The good news is that after about 7 days, female guppies develop a “gravid spot,” which looks like a dark dot near the base of the guppy’s tail.

This is the easiest way to tell which of your guppies are male and which are female.

So, Which is Better to Keep, Male or Female Guppies?

If your goal is maximum color and vibrance, then male guppies are best.

But, if you goal is a diversity of fish that don’t overpower a natural aesthetic but still look elegant, then keeping female guppies along with some rasboras or cherry shrimp is an excellent choice.

Either way, both male and female guppies are a joy to keep.

Guppies vs Betta Fish

Guppy vs betta fish.

I mentioned guppies and betta fish briefly when talking about tank mates, but this is a common question so let me give you a few more thoughts.

Both fish are full of personality and are available in a wide array of colors.

The main difference between the two fish is that betta fish, especially male bettas, cannot be kept together with other betta fish without risking injury or death.

In contrast, male guppies do great when kept together in groups, and seem to appreciate the company fellow guppies.

Male guppies can also be kept together with a wider variety of tank mates.

Betta fish do well with certain tank mates (for example, snails and otocinclus), but will harass or intimidate other types of tank mates, including guppies.

So, if you plan on having a variety of fish in your tank, I recommend getting guppies, but if you plan on setting up a densely planted nano tank, between 3-5 gallons, then I recommend getting a betta fish and letting him/her be the focal point of the tank (they have incredible personalities).


I hope this article helped you become an expert at spotting the differences between male and female guppies.

And, I hope you learned something new about these charming fish!

While common, guppies are incredibly fun fish to keep and make excellent inhabitants for planted tanks because they like to pick at algae and are available in a wide range of shapes and colors.

If you happen to be setting up a new tank and want some ideas for which fish to keep in it, check out my articles on the best fish for a 5 gallon aquarium and 10 gallon aquarium.