Cardinal Tetras Male And Female: Male Vs Female| Differences Explained

Cardinal tetra is a prevalent fish for different reasons. These fish are beautiful, do not need much, and are easy to breed. However, one of the most important aspects that people usually want to know is the differences between male and female Cardinal tetras.

Cardinal tetras male and female are not significantly different. The difference between them is not as apparent as with other species. Male cardinal tetras are a bit bigger, they have a more pronounced dorsal tuft, and their body color is brighter than that of females.

These differences can be challenging to identify because both specimens present colors in blue-green tones, which enhance each other, making it hard to distinguish them.

However, in this post, we will discuss the differences and similarities of male and female Cardinal tetras so that you can see them in a more precise way.

What Are The Similarities Between Male And Female Cardinal Tetras?

There are a lot of similarities between male and female Cardinal Tetras. Some of them are:

Both Male And Female Cardinal Tetras Are Small

Both male and female Cardinal tetras are small in size. The average length of a cardinal tetra is about three to four centimeters long.

Male And Female Cardinals Rarely Fight

The males and females rarely fight with each other. But it’s usually over territory or food rights when they do. You can house them together if you provide them with an ample amount of hiding spots.

Male And Female Cardinals Are Similar in Appearance

The males and females are similar in appearance. The only real difference is that the female has a rounded belly than the male. In addition, both genders have metallic scales that can look golden or silver when placed under light at certain angles.

What Are The Differences Between Male And Female Cardinal Tetras?

There are a few differences between male and female cardinal tetras. Some of them include:

Difference In Size

The most significant difference between males and females is that the males tend to be smaller than the females at around two centimeters long. Males also have a more pointed dorsal fin.

Difference In Coloration

The color of the male is more vibrant than that of females, which are generally paler with less distinct markings. The female has a little rounder body and tends to be more prominent as well.

Sexual Differences

Another difference between male and female cardinal tetras is in the shape of their anal fin. Males have a more pointed end to it, while females tend to be with squared-off edges.

The males are also generally brighter in coloration than females as well. Also, note that you will need to separate the males and the females when breeding these fish, as they will breed if left together.

Preferred Habitat

Male cardinal tetras prefer to live in groups, while female counterparts tend to be solitary fish that sometimes get aggressive towards other fish in their aquarium. Males also display a brighter coloration than the plainer females do and are more active in swimming.

How Many Male And Female Cardinal Tetras Can You Keep In A Group?

This question is quite common to those buying their first tank and wanting to keep a group of cardinals. The answer, regardless of the type you have chosen, be it male or female cardinal tetra, the number should always be equal between both genders for having an optimal development in your aquarium. For example: If you buy five Tetra Cardinals, you should buy three males and two females.

This is necessary to ensure that the couple does not feel stressed or dominated by other fish in your community tank, especially if it’s a male-female pair of cardinals. It also ensures an optimal breeding process when they reproduce their eggs after feeling comfortable with each other.

Can Female Cardinal Tetras Breed Without Male?

The short answer is no. All fishes need a partner to reproduce, so the females can’t spawn eggs on their own. For this reason, you should have at least one male per three females in your aquarium if you want them to lay eggs and raise fry together regularly. But, of course, you can have fewer males if you don’t want to invest much money in the Tetras.

How To Keep Male And Female Cardinal Tetras Safely?

Cardinal tetras are livebearers, and therefore they can breed in a community tank. However, to keep both males and females safe, we must separate them when the females begin to fill with eggs.

However, some of the ways to keep both female and male Cardinal tetras happily in the same tank are:

Use A Bigger Tank

One of the best ways to keep both male and female cardinal tetras in a tank is by providing them with enough space. More giant tanks are always better than smaller ones because they allow swimming room for fish, so if you have an option between different sizes, take the bigger one.

A tank of at least 55 gallons is ideal for a group of cardinal tetras and even better if it is a species tank, which provides them with more privacy and decorations to hide behind.

Ensure The Water Condition Is Optimum

Water quality is of utmost importance for a healthy fish tank. Water should be clean and without chlorine or chloramines and have the proper temperature (20-25 Celsius) and pH level (acidic to slightly basic). You should regularly change the water and clean the filter because male and female cardinals are sensitive to water quality.

Provide A Suitable Environment

Cardinal tetras need a tank with plenty of plants and decorations that shelter them from other fish or potential predators. Providing lots of vegetation allows you to breed your cardinals successfully without requiring a separate tank. You can also use driftwood decorations to break up the sightlines and make them feel safer.


Cardinal Tetras need a tank with average lighting, although if you want to encourage the breeding of your cardinals, more light is better. If you decide to keep them in the species-only tank, make sure the plants they like live with lower lighting and give them some floating vegetation.

Hiding Spots

Cardinal Tetras are schooling fish, and they need to be with their kind to feel safe. Keeping them in pairs is also better for breeding purposes, as you will have females who can be pregnant whenever needed.

If you want to keep your Cardinal tetras safe and avoid their aggression, it is important to give them some hiding space. You can use plants, driftwood, or rocks to create hiding places for your cardinals.

Maintain An Ideal Ratio Of Male And Female Cardinal Tetras

You need to keep an ideal ratio of at least three females per male cardinal tetra so that you can avoid one harassing the others.

A group with less than six fish is not suitable for cardinals. Also, be sure there are no other males in your tank as they might harass or even kill each-others. It is best to keep one male for every three females to avoid any fights for territory.


Are Male Cardinal Tetras Aggressive?

NO! Male Cardinal Tetras are not aggressive, but they have a slightly higher territory to defend. However, they can be territorial with other cardinal tetras, and it is best to keep only one male in the aquarium because two would fight until one dies (or both).

Can Cardinal Tetras Mate With Each Other?

Cardinal tetra fish can mate. These fish show more interest in the opposite sex. They remain motionless while facing each other before mating. Most owners believe this behavior helps them to communicate their readiness for spawning. After mating, the female lays between 100-500 eggs on delicate leaved plants or the aquarium glass.

Do Male And Female Cardinal Tetras Have Different Lifespan?

Male and female Cardinal Tetras do not have a different lifespan. They usually live between four to five years in an ideal aquarium environment. But there are cases of them living more than five years in good conditions.

However, Cardinal tetras grow up fast (about one centimeter per month). So, you must adjust the tank size before buying them. It is because if they get too big for the tank, they will not be healthy.

Are Male Cardinal Tetras More Expensive?

Male and female cardinal tetra fish has the same price in pet stores unless you find an excellent deal on one of them. After that, they can cost up to three dollars each, depending on where you live. The expense of the fish varies according to various factors, but gender is not the case.


In conclusion, we can affirm that there are some differences between male and female cardinal tetras. However, it is crucial to note the importance of each sex in a community tank. Females serve as food for males during their breeding period.

If you want to keep cardinals, it is best to have more females than males. It is because the males will be more aggressive, becoming a threat to their partners.

Hopefully, now you can have more knowledge of this species of fish. So, if you are thinking about keeping cardinal tetras as pets, know that it is a particular type of fish that can bring a lot of joy to your home.

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