(2022) Can Fish Drown? Find Out In This Interesting Article

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When it comes to fish, a lot of us don’t know much about them, except the fact that these beautiful creatures live in water, and they are cold-blooded. Some people might know a few more things than others, for example, those who own fish aquariums or tanks and fish biologists, and researchers know a lot about fish. A lot of people have different questions in mind when it comes to the fish living inside the water. For example, how do fish get oxygen underwater and can drown in the water? The article below contains complete answers about these questions and if they are true or just a myth. Read the article below to know if fish can drown in the water.

Can Fish Drown?

To answer this question, I will need to define two things. First, breathing is taking oxygen inside your lungs from the air, while respiration is taking oxygen using any organ into the body. Second, drowning happens when water enters the lungs and blocks the airways, and cuts the respiration process. Meanwhile, suffocation is blocking the entry of oxygen into an organism. According to this state, fish can drown, they can suffocate and die because of the lack of oxygen. Some people confuse suffocation and drowning as the same. But these are different.

Suffocation happens when an organism is unable to take oxygen inside of its body, in humans, and land animals, the water going into the lungs causes suffocation, which causes drowning and death. In the case of fish species, they can take oxygen from the water. So, they need the water to go inside their gills so that they can take oxygen inside their bodies. But if something happens to their gills, and they are unable to intake water, or filter oxygen from the water, they would suffocate and die.

In this case, the death of the fish would be caused by drowning and suffocation. This happens commonly in many cases. For example, in places where there is a lot of pollution inside the oceans, the fish species die because of suffocation. Pollutants stick to the gills of fish, preventing them from intaking any amount of oxygen and it causes suffocation and brain death because of that.

To get a better idea about this, you should consider a pollutant like crude oil, which spills from ships carrying it. This crude oil is thick and forms a layer over the gills of fish that strangles the fish and suffocates it. Also, the water that has gone inside the fish, would be blocked from coming out, which causes drowning situations. These are a few common examples of the fish being drowned or suffocated inside the water.

Do Fish Need Oxygen?

Yes, fish need oxygen. Oxygen is something that almost all living things need. The main reason behind oxygen being dependent on every living organism is that living organisms need it to break down the molecules inside their bodies that provide them energy. This energy is what keeps them alive, so fish need oxygen. Also, fish need oxygen to help them control their internal cell chemistry.

Water as we know contains some oxygen inside it. The fish intake water inside their bodies, filter oxygen and get the filtered water outside their bodies. It is similar to our breathing cycle, but here the fish uses water as a medium instead of air. We intake oxygen from the air medium that is filtered in our lungs, and we breathe out the oxygen-less air or carbon dioxide enriched air. Similarly, the fish intake water that contains oxygen and they filter oxygen using their gills. After that, they let the water out and the cycle continues.

Unlike human and land-based animals, fish don’t need that much amount of oxygen. The main reason behind this is that the fish don’t need oxygen and energy to control their body temperature. Fish are cold-blooded, meaning that their environment helps them control their body temperature. So, they don’t have to use any energy to maintain it and it helps them live in low energy environments deepwater habitats where oxygen is scarce. The fish only needs oxygen for the metabolism inside their cells.

But, yes they do need oxygen. That is why most fish keepers are advised to use air pumps and need to use a large tank. These strategies will allow you to provide more oxygen for your fish inside the tank and will help you keep them healthy. But a lot of people think that only low oxygen is going to be a problem in their tanks, that is also wrong, too much oxygen inside the tank can also be a problem. It is known as hyperoxygenation. It is identified by the bubbles popping out of the water, and your fish would start to swim with agitation. For that reason, you need to maintain your oxygen level properly. 

How Do Fish Get Oxygen?

The answer to this question is simple: fish intake water, and this water passes through their gills. Gills have the same function as our lungs. It helps fish absorb oxygen and release carbon. After that, the water is moved out of the fish system. Our lungs intake air and filter oxygen, but gills in the fish absorb oxygen from the water. But this is not the only way a fish can get oxygen. Some fish species have a different breathing patterns. These fish are known as air breathers.

It is a type of fish that has a specialized set of gills that is capable of absorption of oxygen from the air. So, you might notice that your fish tries to reach the top of the aquarium and tries to jump out. It is not trying to jump out, instead, it is just trying to breathe oxygen from the air. These fish species are partially amphibious because they live in water but can also survive outside the water. Amphibious fish species also breathe from their skin, which allows them to directly absorb the oxygen into their bodies.

Do Fish Have Lungs?

No, fish don’t have lungs. The process of respiration or oxygen intake in the fish happens using special organs. These special organs of the fish are known as the gills. Each fish contains two gills on the sides of its fish. When a fish needs oxygen, it will intake a large quantity of water and filter it through these gills. The gills of the fish contain multiple blood vessels. When water passes through these gills, the oxygen moves through the vessels into the blood, meanwhile, the carbon comes out of the blood. After this, the fish body expels the water out and the fish gets the amount of oxygen it needs.

What are Labyrinth Organs In A Fish?

The Labyrinth organs are specified organs found in a few species of fish. These fish belong to the suborder of fish known as Anabantoidei. Fish from this suborder have a different type of breathing system as compared to other fish species. Labyrinth organs are an expansion of the gill bones that become a separate organ that also acts as an oxygen filter. But instead of filtering or absorbing oxygen from the water, this organ allows the fish to absorb oxygen from the air directly. It is a unique feature that allows the fish to stay alive even if it is out of the water.

But it is only seen in a limited number of fish species. About 450 species of fish have these organs and the ability. Some of them are also available for aquarium usage and you can easily find and buy one for your aquarium. Dwarf Gourami is one of the best examples of aquarium fish that have these organs. They help the fish stay alive even outside the water but for a limited amount of time and the body of the fish needs to be moist all the time. Without the moisture, fish would die immediately. 

Fish That Breathe From Surface

Yes, fish can breathe. the surface of the water and even outside the water. As mentioned in the paragraph above, some fish species can breathe from the surface of the water as well from under the water. This type of fish species has specialized gills, and labyrinth organs (discussed above.). These fish are known as amphibious fish. Here is a list of the most popular fish species that can breathe from the surface.

  • Gar
  • Gouramis
  • Tarpon
  • Catfish
  • Rockskipper
  • Mudskipper
  • Mangrove Killifish
  • Normal Eels and Swamp Eels
  • Some Catfish
  • Labyrinth fish

Apart from these, there are other hundreds of examples of fish that are capable of living outside the water. Some of them can do it just for a moment, while others can do it for a long time.

How Do Fish Gills Work?

The gills of fish work the same as the human lungs work, but the medium is different. Our lungs have capillaries lines in them, the same way fish gills have capillaries that are filled with blood. These thin capillaries allow the flow of oxygen and other molecules when the water is moving through the gills. Fish intakes water through the mouth, which travels towards the gills. Gills receive this water and run it close through the capillaries, and the exchange of oxygen and carbon dioxide happens. After that, the water moves out of the fish body through these gills that open outside. For a fish to successfully respirate under the water, these gills are crucial. Any kind of damage to the gills of fish can cause the fish to suffocate, and drown. That is why you need to protect the gills of your fish inside the tank.

Suffocation and Drowning

Suffocation and drowning are two different things. Drowning is a form of death that occurs because of suffocation. Drowning happens when the flow of oxygen to the body is restricted, and organisms are unable to respire. For a land animal, anything that can hurt lungs, airways can cause suffocation. For a fish, suffocation happens when the gills are not working properly or have been damaged. Or the fish is unable to intake water. By using the definition of drowning, it can be said that fish can drown in the water.

How Do Fish Breathe In Water?

Fish do breathe, but this is different from human breathing. Because when we breathe, we intake air into our lungs and from there the oxygen is filtered into our bloodstreams. Meanwhile, in the case of fish species, this medium of air changes into water. So, for breathing, the fish intakes water, and then the gills help it absorb the oxygen. This is how breathing occurs in the fish species. There are specialized capillaries in the fish gills that allow them to exchange oxygen and carbon when the water is moving through the gills.

Can Fish Suffocate and Drown Underwater?

Yes, fish can suffocate and drown. This happens when the gills of the fish are damaged, or waterways inside the fish body are damaged. This damage can be caused by shock, an injury, or infection and diseases. Once that happens, the blockage causes the fish to suffocate as it would not be able to properly exchange the oxygen and carbon in the water. This would lead to brain death in the fish.

It is one of the common causes of death in fish inside the aquariums. The low oxygen content of the tank causes the fish to slowly suffocate because of the shortage of oxygen. Apart from this, any kind of injury to the lungs, mouth, or the fish itself will also cause this. For that reason, it is very important to keep your fish in a tank that has a balanced amount of oxygen and that contains a clean, hygienic, and peaceful environment.

Reason for Fish Drowning:

The main reason is a blockage, physical injury, an infection that causes the waterways of the fish body to stop working. Fish will not be able to intake water, hence the gills will not be able to provide oxygen. If this continues the fish would die because of drowning. Here are some of the reasons for the drowning of fish.

  1. Blunt Force Trauma
  2. Infection or Disease
  3. Low Oxygen in tank
  4. Unhygienic Condition (oil spill in seas or other forms of pollution.)
  5. Algae blooms cover the surface.

Why Keeping The Aquariums Clean Is Important?

Keeping the aquariums clean is very important to avoid the drowning of fish. If you do not keep your tanks clean, the chances of algae blooms, infections, and diseases in your tank will be higher. These can cause low oxygen issues in water, which can lead to suffocation and death of your fish. You should clean your tanks regularly because it will help you prevent the growth of algae. Recycling the water of your tank will allow you to clean your tank from bacteria, and parasites that can attack and kill your fish in the aquariums.

Why Is the Size of a Tank Important?

The size of the tank is very important for the fish. You should always go for a large tank that can hold more fish. But this is not the only reason why you should select large tanks. The main reason behind the selection of a large tank is that a large tank will have more surface area. More surface area allows more oxygen to be absorbed into the water. This helps you enhance the level of oxygen in your tank and prevent the suffocation of your fish.

Expert fish keepers advise about selecting a tank that is long, and wide, instead of selecting a tall tank. Taller tanks can have smaller surface areas, but the tank with the same capacity but a longer and wider size can have more surface area, hence providing more oxygen to the fish in the tank. Also, the large tanks prevent the territorial skirmishes between the fish in the tank. This helps you prevent any kind of fights and possible damage to the gills of fish that can also lead to the death of the fish. For these reasons, it is very important to select a tank of large size and more surface area.

Signs of Low Oxygen in Aquariums

If the oxygen content in your aquarium is low, you will notice that your fish has become more agitated. They will swim at random and will be showing signs of abnormal behavior. Apart from this, your fish will also be moving their gills very fast. They would be doing this to compensate for the low oxygen content. When the content of oxygen in your tank becomes low, your fish would need to intake more water to get more oxygen and that is why their gills will be moving too fast. It would be an indicator that the oxygen content in your tank is dangerously low. It can easily kill all of your fish inside the tank. There are a few strategies that can help you alleviate the oxygen levels of your tank.

What Causes Low Oxygen In Aquariums and How to Solve It?

There are several reasons for low oxygen in aquariums, these include overcrowding, using small tanks for more fish, large fish, and others. If you want to become a successful fish keeper, you will need to learn about providing more oxygen and proper care to your fish. You need to avoid overcrowding, maintain your tanks properly, prevent algae growth, maintain temperature and water movements, maintain salinity and hardness of the water. There are other detailed solutions that you can use such as installing an air pump into your tank. An air pump will intake oxygen from the air and will pump it into the water, hence immediately allowing for more oxygen absorption. It is mostly needed for very small tanks with large numbers of fish.

Low Oxygen Vs Excessive Oxygen In Tank

Low oxygen is not the only problem, sometimes, excessive oxygen in the tank can also be a problem. An excessive amount of oxygen in a tank is known as hyperoxygenation of the tank. Hyperoxygenation can also be a serious problem similar to low oxygen. It changes the chemistry of water and causes bubbles to form. These bubbles move to the top and then pop up. It can also kill your fish and make them go crazy. Fish in the tank where there is an excessive amount of oxygen can become dangerously active, and agitated. It can also lead to the death of the fish in severe cases. For this reason, you should prevent it from happening.

Reasons For Low-Level Oxygen In-Tank and How To Improve Oxygen Level In Your Tank?

Here’s a list of some of the reasons for low oxygen in a tank.

●     Overcrowding Of Tank

Putting too many fish in the same tank is never a great idea. It leads to fish fighting each other, and it can also lead to oxygen level issues. More fish would need more oxygen and a smaller tank cannot provide that much oxygen. This leads to more demand and a low supply of oxygen which can lead to health complications for every member of the tank. For that reason, expert fish keepers advise that you should use a small tank only for a limited number of fish. It is better to calculate the size of the tank based on the fish per gallon ratio. It will help you know the exact number of fish that you can put inside a tank.

●     Excessive Algae Presence

Excessive algae presence can also be a problem for your tank. Excessive algae formation in a tank can lead to algae blooms. These blooms cover the surface of the tank and prevent oxygen absorption. Hence, causing the oxygen levels to plummet inside the water. For that reason, it is important to keep your tank clean of algae. You can do it by adding fish that eat algae, or aquarium species of snails, that eat the algae. Most importantly, you need to clean your tank regularly and recycle the water within the given day’s limit for each tank. A clean tank would prevent algae growth and would help you maintain the proper oxygen levels.

●     Poor Maintenance

Poor maintenance of the tank can also cause low oxygen level issues for your aquariums. Maintaining includes properly cleaning your tank, controlling the parameters, and maintaining a perfect habitat inside the tank. If you fail to maintain that, your fish would be at the risk of suffocation because of the low oxygen.

●     Temperature Issues

Changes in the temperature can also lead to absorption issues in your tank. For example, on hot summer days, water from your tank will become hot and it will cause the oxygen to move out of the tank in the form of bubbles or air vapors. It can lead to a severe oxygen shortage in the tank. Apart from this, too cold temperatures are also not good for the fish inside the tank. Fish are not properly able to absorb oxygen from too cold or too hot water. This can lead to the problems of suffocation and death and you can prevent it by maintaining the temperature in your tank properly.

●     No Water Movement

Movement in the water is also important because the fish breathe water when it is moving. So, if the water inside your tank is still or it is not moving at the recommended speed, it can also lead to low oxygen in the fish blood. The gills of the fish are developed in a way that allows them to breathe while the water is moving because most fish species live in those places where there is a constant movement in the water. You should use air pumps, and water filtration systems to create vibration and movement inside the tank.

●     Smaller Surface Area

The smaller surface area of the tank as discussed above can lead to low oxygen absorption. It can then lead to the low oxygen content in the tank. It is the reason why it is recommended that you should get a large tank. Preferably a large tank with more surface area, a tall tank will have less surface area as compared to a tank that is wide and long. So, you should always select an appropriately sized tank.

●     Too Many Plants

A lot of people put too many decorations and plants in their tanks. This leaves only a small space for their fish to swim, and move in the tank. Although adding the plants in the aquarium adds oxygen, it can also lead to several other issues which can cause low oxygen content in the tank. But it can be prevented by only planting one or two necessary plants in your tank.

●     Chemicals In Water

If you are using the tap water for the tank without filtration, you might be causing your fish to drown. This is because most of the tap water contains chlorine and additional chemicals that are harmful to the fish’s health. Also, these chemicals prevent oxygen absorption in water. This can lead to the low oxygen content in your aquarium. It can be prevented by using properly cleaned and filtered water.

Can Fish Drown When You Pull Them Backwards From Aquariums?

Yes, pulling the fish backward can also drown them in your aquarium. This is because the gills of the fish only allow the water to move out, but when you drag the fish backward in your tank, you cause the water to go into the gills from the closing side. This can lead to the death of fish as the water from the mouth would not be able to reach the gills properly and it can badly hurt your fish. It is never a good idea to drag or pull your fish backward.

Can Fish Breathe Outside The Water?

Yes, some species of fish can breathe outside the water, these are known as the amphibious fish species. These species have evolved and developed several mechanisms that allow them to stay alive outside their natural habitat. But there are two limitations, first, there is a time limit. Some fish can live for 10 minutes or less in outside conditions, while some fish can survive for long.

Can Fish Breathe Air?

Yes, some fish species can breathe air. These have specialized organs that allow them to intake oxygen directly from the air into their bloodstreams. These fish are known by multiple names including amphibious fish, rock jumper, mudskipper, and more.


In the article above, we discussed the answer to the question “can fish drown” and some other questions surrounding the same issue. The fish can drown in the water. But this drowning will be different from some land-based animals drowning in water. This drowning would be because of the fish’s inability to absorb oxygen from water into their bloodstream. It can be caused by several issues such as bacterial and viral infections, injuries, waterways being blocked, and more. Also, low oxygen in the tank can kill your fish. But you can prevent all of this by properly maintaining the aquarium conditions.

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