Are Cardinal Tetras Fin Nippers: Answering Your Queries

Cardinal tetras are a widespread freshwater fish that most hobbyists have at least a couple of in their tanks. Cardinal tetras are very easy to care for and can be a great beginner fish. One of the reasons for the immense popularity of these fish is their peaceful attribute. But some owners complain that Cardinal tetras are fin-nippers. What’s The Truth?

Yes, Cardinal tetras are fin nippers. These fish are omnivores that enjoy eating plants and small invertebrates. However, they will not hesitate to nibble on the fins of other tankmates if given a chance. They also have a reputation for being rather aggressive in smaller tanks with little plant life to compete over resources with others.

If you are new to Cardinal tetras, you might be curious about a lot of things. Read this post for more information about these exciting fish.

What Is The Temperament Of Cardinal Tetras?

Cardinal Tetras are peaceful fish that can coexist with most other community species. They are not aggressive and do well with other Cardinal Tetras, as they prefer to live in schools.

Cardinal Tetras also get along with other non-aggressive species of fish that need water temperature (73 to 81 degrees F) and pH levels (4.6 to 6.2) to thrive in water. However, avoid keeping them with larger or more active predators such as Tiger Barbs or Oscars.

Are Cardinal Tetras Fin Nippers?

Despite being a peaceful fish, Cardinal tetras are fin nippers. It would be best if you never kept them with any slow-moving fish because they will attack them, no matter the other fish’s size. Cardinal tetras mostly go after long-finned or slower swimming types of fishes when they feel threatened or in an aggressive mood.

If you have a tank full of Cardinal tetras, you need to be careful that they do not go after the other fish, or it will become a challenging task for you. You can keep Cardinal tetras with some fast swimming fish like tiger barbs and danios but keep in mind that Cardinal Tetras are fin nippers.

Why Do Cardinal Tetras Start Fin Nipping?

Cardinal Tetras are usually fin nippers. Cardinal tetra fish start this behavior due to several reasons such as:

Due To Inadequate Space

Cardinal tetra fish are small in size. Therefore, they require adequate space to swim around and feel comfortable in their surroundings. When they do not get enough space, Cardinal tetra fish become fin nippers.

Cardinal tetra fish usually show fin nipping behavior around the size of 1.2 inches. But, again, it is because they can’t swim around and feel comfortable in smaller tanks.

Cardinal Tetras Are Not Feeling Comfortable

Another reason behind Cardinal tetra biting their fin is feeling uncomfortable due to surroundings. Cardinal tetra fish are susceptible creatures. Thus, if they do not feel comfortable in their surroundings, they will start fin nipping activity to get rid of that feeling.

Cardinal Tetra Fish Are Not Getting Proper Nutrition

Cardinal tetra fish do not fin nippers due to nutrition, but they can become one if they do not get proper nutrients. Therefore, they require specialized diets which include meaty food items such as brine shrimp or blood worms.

If you have been feeding your Cardinal tetra fish with frozen food, you must start providing them live food. Cardinal tetra fish can become fin nippers if they do not get appropriate nutrition.

Due To Boredom

Cardinal tetra fish are very active creatures. If Cardinal tetras do not get proper mental stimulation, they will become fin nippers.

Cardinal Tetra Fish requires appropriate toys to play with, such as plants and rocks, to prevent boredom. Unfortunately, when these fish feel bored, it can cause them to start fin biting behavior which is a bad habit.

Cardinal Tetra Fish Become Fin Nippers When They Sense A Threat

Cardinal tetra becomes fin nippers during stress and danger. Since these fish are susceptible creatures, they feel any threat in their surrounding. So, they start to nip the fins to calm themselves down and in self-defense.

So, if Cardinal tetras feel that there is some threat in the water, such as larger fishes or other Cardinal Tetra Fish nipping at them, these fish will become fin nippers to get rid of that feeling.

Fin Nipping Is A Sign That Cardinal Tetras Are Sick

Fin nipping is an unusual behavior that Cardinal tetras show when they are sick. When these fish are ill, they feel uncomfortable and vulnerable. Thus, they will start fin nipping. Usually, the most common disease that can lead to fin nipping is a parasitic infection. 

Therefore, if you suspect your Cardinal tetra is sick, you must check their fins. If there are signs of missing scales, fin rot, or fin nipping, these fish might be ill.

Is Fin Nipping Serious Problem In Cardinal Tetras?

It can be a severe problem. Cardinal tetras are famous for their bright colors, but fin nipping is not a common problem. If your cardinal tetra has its fins bitten off by other Cardinal Tetras, it will grow back fine.

However, the long-term effects may cause more harm than good to your fish tank inhabitants because these bites can become infected. In addition, Cardinal Tetras are also nip the fins of other Cardinal Tetras with less color or duller colors than themselves, resulting in fin rot.

How to Stop Cardinal Tetras From Fin Nipping?

Fin nipping can be a severe problem in Cardinal tetras. Sometimes it can also lead to the death of your Cardinal tetra. So it is because fin nipping can lead to infection, wounds, and even bites.

Thus, it is important to stop Cardinal tetras from fin nipping. Moreover, some of the ways to stop fin nipping habit of Cardinal tetras are:

Keep Cardinal Tetras With Peaceful Tankmates

Cardinal tetras are peaceful fish. So, it would be best to put Cardinal tetras with the tankmates that will not nip their fins or provoke them in any other way. The best tankmates are Black Phantom Tetra, Glowlight Tetra, Other Cardinal Tetras, and Panda Cardinal Tetras.

Regularly Change The Water

Cardinal tetras are a very active type of fish. Cardinal Tetra Fish requires clean water to stay happy and healthy in the aquariums. So, it is best to change about 30% of the tank’s water every week or when you notice some dirty water in your Cardinal tetra tank.

Make Sure That Cardinal Tetras Have Enough Room

Cardinal tetra fish require a lot of space to stay happy and healthy. So, it would be best to keep Cardinal tetras in spacious tanks rather than small tanks or bowls. Also, ensure no overcrowding at your home aquarium because overcrowding can lead to fin nipping issues among Cardinal tetras.

Maintain The Required Water Conditions

Cardinal tetras are a type of fish that are very sensitive to changes in water conditions. Cardinal Tetra Fish requires stable pH and temperature levels at all times, so it is best not to change the aquarium’s environment drastically. It is best to maintain the tank’s water at a pH level of about 4.6 to 6.2 and temperature between 23°C – 25°C.

Keep Cardinal Tetras in A Peaceful Environment

Cardinal Tetras likes to live in peaceful surroundings, and they feel stressed when kept in a small tank. Thus, please provide them with gentle water currents so that fin nipping can stop within weeks.

Sometimes you can prevent fin nipping by keeping Cardinal Tetras in a peaceful environment with their kind or even alone. So, ensure that Cardinal Tetra Fish stays in a relaxed atmosphere that is free of stress.

Use Plants And Decorations

Cardinal Tetra fish love to hide and move around in plants and decorations. Thus, using plants and decoration is an easy way to stop fin nipping Cardinal tetras. Moreover, it will also give them a peaceful environment to sit without fearing their tankmates’ attacks.

Give Them Suitable Food

Cardinal Tetra fish are omnivores. They eat flakes, pellets, and live food as well. Therefore, you should give them high-quality flake foods daily to keep them healthy and happy. In addition, they also love live daphnia crustaceans that can prevent the fin nipping habit of Cardinal tetras for good.

Some FAQs

Do Cardinal Tetras Attack Each Other?

Cardinal tetras are peaceful fish and won’t attack each other. Carfishl Tetras are pretty timid, and fin nip is probably a sign of aggression, but they will do it to any tetra that swims too close to them.

What Is Fin Nipping?

Fin nipping is when Cardinal Tetras attack the fins of other Cardinal Tetras. Cardinal tetra fish sometimes act as fin-nippers. They usually target sick or injured Cardinal Fish, resulting in infection, deformed growths on their wings (fin rot), or complete loss of one or more fins.

Are All Species Of Cardinal Tetras Fin Nippers?

Some Cardinal tetras are fin nippers, but not all of them. For example, Congo Tetra (Phenacogrammus interrupts us) and Glowlight Tetra (Hemogram erythrozonus), both belonging to the Cardinal Family, are not fin nippers.

Can You Keep Cardinal Tetras With Other Fish?

Yes, you can keep Cardinal tetras with other fish as long as their tank is clean and not fin-nippers. However, it is best not to keep Cardinal tetras with species like Glowlight Tetra (Hemogram erythrozonus), Black Skirt Tetra (Gymnocorymbus ternetzi), and Ember Tetra (Hyphessobrycon amandae).


Summing up, there are usually different responses from Cardinal tetra owners. Some say they are fin nippers, while others claim Cardinal tetras never bite or chew on fish fins. Of course, it depends on their living conditions and tank mates in the case of Cardinal Tetras, but it is safe to assume that any other fish with long tails may become a target for Cardinal Tetras.

If you want to keep Cardinal tetras with other fish, it is best to get them when they are small and see how they go once fully grown. Just like other tropical fishes, Cardinal tetra fin nipping occurs in the vast majority of cases. However, when you succeed in keeping them in the proper environment, Cardinal tetras are a lovely addition to any fish tank.

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