How Do Tetra Fish Sleep? Ensure They Get Enough Rest

Do Tetra Fish Need Sleep? How do they sleep?

Sleeping is an integral part of the life cycle of any living being just like breathing, eating, and reproducing. Mammals, birds, insects, and fishes all sleep, but the way of sleeping is different for different creatures. In the case of fish, there are several different ways of sleeping for each species. Some shoaling and regularly swimming fish are suspected of remaining sleepless for their entire life. But this article discusses the sleeping nature of tetras. So, do tetra fish sleep? If yes, then how do they sleep? I will answer all of your questions below.

In this article, we will be looking at the sleeping nature of tetra fish, and after reading this, you will know when your fish is asleep. Trust me. This is helpful because sometimes you may think your fish is dead when it is just having a nap. This article will also tell you about how different types of tetra fish sleep.

Do Tetra Fish Sleep?

Like most of the other tropical fish, tetra fish also sleep. Although tetras are shoaling fish and are always in motion, when you turn off the lights, they show behaviors that resemble sleeping. Cardinal tetra, neon tetra, and other common tetras have similar sleeping styles.

Fish-keepers often say that schooling fish never sleep and are always in constant motion. This fact can be actual for most of the schooling fish out there but not right for tetras.

How Do Tetra Fish Sleep?

If you have been keeping tetras for a long time (neon tetras, for example), you must have noticed that when you turn on the lights in the tank after exposing the fish to darkness for some time, their body seems pale. Yes, this is a common thing, and it is not a deformity in your fish. Tetras with distinct colors like cardinal and neon tetras have this feature. This color-changing property in tetras is associated with sleeping.

How tetras sleep is similar to the sleeping style of other fish. These fish do not close their eyes but can sleep for a couple of hours. Tetra keepers have reported that they can see their fish floating almost vertically at the lower section of the tank near the gravel. You might also see neon tetras and cardinal tetras changing color after you have turned on the lights after some time. At the day, the lateral stripe on their body is blue-green, which changes to indigo in the darkness. This color change is also said to be associated with how they sleep.

All of the tetras are middle and bottom dwellers. They swim in the middle of the tank for the whole day, sleep at the bottom, and only come to the top for food. In the wild, tetras sleep while maintaining teamwork. Some fish in the school serves as the eyes of the school looking for predators while others sleep.

Also Read: Can Different Types Of Tetras Live Together

What Is Proper Light Scheduling For Tetras?

For your fish to sleep, light scheduling is vital. If you turn on the light all the time, sleeping might get difficult for your fish. Too much lighting can not only deprive your fish of sleep but also give it stress that can result in death. Also, more light means more heat, which is not something that you want in your tank.

For neon tetras, subdued lighting for 12 to 14 hours a day is mandatory. For the remaining hours of the day, you must turn off the lights completely. If the tank is densely planted, which is compulsory for some tetras, then the light intensity must be increased from subdued to high.

If you want to know more about the tetra tank set-up, then click here.

Do Neon Tetras Need Light At Night?

Like any other tropical fish, tetras require light and darkness both to complete the circadian rhythm or their daily routine. But at night, when you turn off all the lights in your room, it is the best time to deprive them of the tank lights. This way, tetras can sleep at night, and their average daily cycle can be completed.

At night it is relatively easier to maintain a blackout than at the day. So, fish will tend to sleep at night when there is complete darkness around them to complete the circadian rhythm.

How To Tell If My tetras Are Sleeping?

As a fish-keeper, you must be able to distinguish when your fish is asleep. This is important because you can sometimes be mistaken, sleeping for death. Although sleeping and death can sometimes be hard to differentiate, it is not that impossible. To know if your fish is sleeping or not, you just have to look after some signs that your fish will exhibit.

If your fish if floating with the stream or the current of the filter and is not showing any fin movements, then it is safe to assume that it is dead. However, is the fish is floating at the same place without the current affecting it, it is probably sleeping. Also, during sleep, fish are quite alert, and they will respond to your tapping on the tank walls. However, this is not a safe way to check whether the fish is asleep or not, as this gives them stress.


As a fish-keeper, it is your responsibility to allow your fish a complete rest. So, you must be able to tell when your fish is asleep without waking it up.

If you have made it here, I think you have read all the above sections carefully. It is essential to know about your fish sleeping, and the parts above will help you. I guess I have answered all the queries regarding the sleeping nature of tetras.

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