This Is Why Your Zebra Danios Are Not Schooling!

Zebra danio, also known as, zebrafish is very popular species among the aquarium enthusiasts originating from the Cyprinidae family. Zebra Danios are easy to take care of for new hobbyists and therefore, more popular among them. The majority of people are often wondering why their zebrafish are not schooling. In this article, we would like to talk about this topic.

Zebra danios do not school in normal conditions, since they feel quite comfortable in the environment. Therefore, you only need to worry if they are schooling as this is a way to exhibit some kind of stress.

This topic can be quite confusing for rookies in the aquarium hobby. You will face a lot of strange manners from different fish species and you have to get familiar with them to prevent further difficulties. Generally, zebra danios are considered to be schooling fish but only on specific occasions. We are here to provide information regarding this behavior. Let’s start!

Do Zebra Danios Go To School?

The main and most significant reason behind schooling behavior is the stress factor.

When your zebrafish is not living in a comfortable environment, it induces them to start schooling. So, if they are not swimming together identically it’s simply because they live an extremely joyful life in your aquarium.

As for the stress, there are a lot of factors affecting the happiness of your zebra danios. We would like to list some of the most well-known symptoms of stress in order to make identifying and preventing them easier for you.

  • Losing of Appetite – it is one of the most easily noticed symptoms when fish is stressed. They will start refusing to eat what they consume daily and it is a sign that something is bothering them.
  • Swimming at the Surface – If the water conditions are not suitable your zebrafish might start gasping his mouth at the surface. It is mainly caused by the lack of oxygen and fish will get stressed if you don’t take care of it.
  • Diseases – Aquarium fish is vulnerable to several diseases and we encounter diverse symptoms in this case. When danios are stressed, some white spots might appear on their bodies and you should immediately seek treatment.
  • Strange Behavior – Usually, when fish are stressed, they will show weird manners such as swimming frantically, laying at the bottom of the tank, locking fins at his side, and so on.

Why Zebrafish Danios Fish Get Stressed?

Next, we want to point out some of the causing factors for stress in aquarium fish and provide necessary suggestions to prevent it.

This Is Why Your Zebra Danios Are Not Schooling!
This Is Why Your Zebra Danios Are Not Schooling!
  • Poor Water Conditions – You should make everything suitable for your danios. You have to constantly check water temperature, ammonia and nitrate levels, pH, oxygen level, and so on. If any of these factors are violated fish is under a serious risk of developing stress.
  • Change of Environment – Fish are often very sensitive towards their environment and when you move them to another aquarium it will most likely induce stress. Therefore, you should do it carefully and consult with an expert to avoid any complications.
  • Incompatible Tank Mates – The majority of aquarium fish bear a strong resemblance to humans when it comes to compatible neighbors. Not all fish get along well which leads to several problems such as fighting, aggression, and stress.
  • Improper Diet – It is extremely important to feed your danios with proper food and to include every necessary nutrient. A suitable diet makes fish’s life much longer and healthier, otherwise, the lack of nutrients will most likely lead to stress.
Zebra Danio Schooling
Zebra Danios Schooling

Zebrfish Danios is a major model organism to study the developmental, physiological, and genetic basis of the stress response. Check out a very informative article on Stressing Zebrafish here.

How Do You Help A Stressed Fish? 

If you notice any of the above-mentioned symptoms then it is time for you to take some actions. We have noted the major causing aspects of stress and you have to check each of them very carefully. When you identify the main issue, it is necessary to fix and make it suitable for your zebra danios.

To Reduce stress in your Zebrafish, utilize a water quality test kit to ensure the best quality of water in your aquarium. Also, it will be good if you set up a filter to clean the water every once in a while and create a healthy environment.

You have to refrain from adding too many fish in the tank to avoid fighting and aggressive behavior which often results in stress. Make sure to place compatible species together! Finally, it is necessary to be informed about the diet of zebrafish in order to provide every essential nutrient and make a healthy life for it.

What Type of Danios School?

We have noted above, that danios are social individuals and they are willing to live together with their kind as well as other species. Although all types of danios can reside peacefully in the tank it’s recommended to keep no less than 5 of each type – preferably 4 females with 1 male.

We want to compare zebra danios with other species of danios and describe the relationship between them. This way, you will have a better idea about the tank mates of your zebrafish.

  • Leopard Danios – they are subspecies of zebra danios and will gladly school together in the aquarium. It will be best to get minimum of 5 leopard and zebras if your tank is 30 gallons or more.
  • Pearl Danios – zebra and pearl danios are not of the same species and therefore won’t school together in the tank. However, if they are placed in an environment with few species, they might try to swim together in order to suppress the feeling of loneliness.
  • Giant Danios – they are twice as big as danios and needless to say, you should get a relatively large aquarium for them. Our suggestion would be to go for a 50-gallon tank and they will happily school together oftentimes.
  • Blue Danios – their appearance is pretty much the same compared to danios except for the white stripes along the sides. It’s very easy to keep them alongside zebra danios and they will often school together.
  • Rosy Danios – They resemble pearl danios to a great extent and also, they are perfect tank mates for your zebrafish. They will most likely not school together but your aquarium will have a peaceful environment with both of them inside.
Zebra Danios Schooling Together
Zebra Danios Schooling Together

Other danio species include cross banded danios, Malabar danios, and gold ring danios. On most occasions, they will make a comfortable relationship and successfully school with your zebrafish.


In this article, we have described the schooling behavior in one of the most popular aquarium fish called zebrafish. The majority of people are interested in reasons why they might be showing this behavior and the answer is stress. When your zebrafish are experiencing stress, they will most likely start swimming together.

It’s highly unlikely for them to start schooling when they are living stress-free life as this behavior is meant to be some sort of defensive measure. So, if you keep everything under control and make a comfortable environment for your danios, they will most likely not school.  

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