Are tetras schooling fish? Why is Schooling Important for the Tetras?


Tetras are colourful, calm, and most peaceful fish, and it’s this feature that makes this fish ideal for all hobbyists, it may be for beginners or advanced. Many people, before buying tetra fish for their aquarium, usually have a common query. 

“Is tetra a schooling fish?”

Yes, tetras are schooling fish that do best in the well-established aquarium. Before going deep into this question, the first important thing to know is “What exactly a schooling fish is?”

What is Schooling fish?

Schooling fish is a group of fishes that stays together for social reasons and swims in the same direction in an adequately coordinated manner. The view of schooling fish is so awe-inspiring and mesmerizing. It is so peaceful to see a large group of fish swimming back and forth in a perfectly coordinated harmony. 

How Schooling fish differs from shoaling fish?

Though both of these terms describe the behaviour of the fishes, yet they are actually different things. 

Shoaling is the behaviour of the fishes where they hang out in a loose group in the same place. While in schooling behaviour, fishes move together in the same direction, at the same time, and all at the same speed.

Schooling fishes generally stay together and move in the same direction. But if they stop doing so, they become shoals. 

All the obligate schooler fishes and obligates shoaling fishes spend together, and in such case of separation from the group, fishes may feel highly stressed.  

While the facultative schooler fishes and shoaler fishes only come together for some special functions or purposes. The rest of the time, they live individually separated from the group.  

Why do the Tetras fish school?

Though the proper reason for the fish to school is not known, still many scientists believe the reason for the schooling is protection- safety in numbers. It is considered that the attack by predators decrease multiple times when several hundred of thousands of fishes are together. 

The predator is more likely to attack single, separate fish rather than thousands or hundreds of fishes in a group. Also, it is easier for the group of fishes to search for the food and secure it with more eyes and mouths devoted to the food searching task. 

These are the reasons that make tetras travel in packs and forage on algae in large groups. Another reason for schooling is mating as it improves the ability of the fish to find a mate and reproduce successfully.

Schooling behaviour makes the eggs to fertilize more likely in a large group. With so many produced eggs, more eggs are likely to escape from the predation by other fish.  

Also, the schooling behaviour of fishes helps in improving the hydrodynamics of each fish individually and makes them conserving energy by easily move through the water. 

How does schooling in tetras work?

Tetra fishes keep the school together with the help of a combination of senses. The key to keeping the school together is vision. Other senses like smell, sight, the lateral line, and the use of pheromones are also helpful for the fishes to determine what their position in the school is and what the school is doing.

None of the fish is a leader in the group; in fact, all fishes stay in communication with their neighbour fish. In case when there is an increase in the speed of this fish, or it turns, the other fish react in kind. 

There are two zones for each fish- one is the zone of repulsion which helps them to keep an equal distance from the neighbour fish, and another zone is the zone of orientation that helps the fish to do the same as the next fish is doing. 

In a moving schooling fish, each and every fish tries to match their neighbour fish. In case when the school is stationary, each and every fish stays close to its next fish. 

What cases make Tetras don’t school?

Sometimes people come to us with a query that their tetra fish is not schooling. Well, there may be several reasons for this. Any fish that have been moved will be stressed. Stress makes the fish behave atypically. 

Also, schooling behaviour is seen for defence. In case of a threatening environment, the fishes for a school to minimize their personal risk. In a crowded small tank, the fishes are less likely to feel threatened. This makes them show behaviour other than schooling. 

Can different types of tetra fishes live together?

The answer to this question is Yes, only in case when there are sufficient members of each species present to form a different school. 

The same species of tetras make school together and can live well only in condition when they are enough in number.

If you wish to fill your aquarium with different types of tetra fishes swimming mesmerizingly when kept together, all you need is to get 6 of each species so that they can have their school. 

Can different types of Tetras fishes form a school?

This is quite a tricky question. And the answer is both yes and no. 

In general, the answer is no, because tetra fishes prefer to form school with the member of their own species. But sometimes, tetras can make a school with different species too. 

Also, sometimes the similarities in colour, size, and requirements of different tetras make them live together and form a school. 

The best example of this situation is Neon Tetras and Cardinal tetras that are the most common pair to form a school together.   

Why is Schooling Important for the Tetras?

As we humans also seek for a company to live with, similarly fishes do the same. Some Tetra fishes can also live alone but living together in school increases their lifespan. 

Tetras fishes are adapted to survive in a school, and they prefer to live together in their artificial aquarium. Also, the group makes them feel stronger. This is the reason why tetras live together and form school. With sufficient members in school, they feel safe and sound. 

When the school contains more number of the same fish species, they can easily protect themselves from the predators and larger fishes. 

The movement of fishes in coordinated harmony confuses the larger fishes and other predators, and this makes them not focus on individual prey. 

What happens when Tetra fish is separated from the group?

In case when tetra fish is alone, it shows several health issues. If separated from school, the tetra fish have a tendency to get depressed. 

Depression is not a simple disease, but a set of biological symptoms that includes appetite loss and sluggishness. These symptoms can be fatal for the tetra fish as they may stop eating and swimming, which is essential for them to stay healthy. 

The Bottom line

In a nutshell, all we want to say is, if you want tetra fishes for your aquarium, always keep them with their school. 

If you want different tetras for your aquarium, keep 4 or 6 members of each tetra with respect to the tank size. 

Different types of individual tetras may not be together, forming a school, but you can easily keep their schools together in the same tank.

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