Do fish come up for air?

Table of Contents

As we mostly know, fishes respire through their gills, in a process where water enters into their gills for them to begin the process of respiration. There are several elements in water, which work together for the wellbeing of the fish. In water, almost 80% is constituted of nitrogen, with less than 2% percent allocated to other elements, and 20% of water is made up of oxygen. Like most living things, fishes also need air to survive- this is known as aerobic respiration. Meanwhile, just like in humans, energy from respiration can be produced not just by aerobic respiration but also by anaerobic respiration. However, anaerobic respiration cannot sustain any living thing that uses oxygen to produce ATP, hence, the need for them to come out for atmospheric oxygen when there is a shortage of oxygen in the water. Oxygen is also needed for the regulation of some skin functions. Fishes typically use the oxygen molecule in water (H2O) to respire. Hence, when the water is polluted or filled with lots of feed or looking murky, the fish would not respond appropriately.
The long-awaited answer to the question, “Do fish come up for air?” is a big, Yes!. Fishes come up to get air; they come up to the surface of the water to get environmental oxygen, especially when the oxygen inside water is not sufficient or in the case of absence of oxygen due to pollution. Debris and dead matter can lead to water pollution, which makes the fish want to find a way out. Also, when the water body temperature is high- which usually happens during summertime, it can reduce the oxygen content of the water and make it uncomfortable for the fish to stay deep in the water.


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Do fish come up for air

Do All Fish Need To Come Up For Air?

Fishes breathe air through their gills, as said earlier but, in the case of aquatic mammals, gills, although an option in some, however, it is not their main respiration method. They respire like typical mammals- through their lungs, by an exchange of air between the atmospheric air and their lungs. As earlier said, fishes are no different from other animals because they need oxygen to function properly. During very hot seasons, the dissolved oxygen level may be reduced due to the evaporation of most of the water back to the atmosphere. This hot season, regardless of whatever name it is called in any region- summer or dry season, is a very uncomfortable time for fishes. That’s why they leave their comfort zones, to be able to respire normally. Although the above stated is valid, still, there are some fishes with absolutely excellent survival skills. The survival skills are limited to their ability to adapt in a condition whereby the oxygen of a water body is reduced. This type of fish uses anaerobic respiration to produce alcohol and ATP. Few examples of fish that exhibit this phenomenon are; crucian carp, salmon, and trout. Among the three mentioned, the crucian carp has the highest susceptibility to oxygen drop in water. It survives by anaerobic respiration in a duration, probably longer than in some fishes. This fish might not need to come out of the water to get atmospheric oxygen. 

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On the other hand, Salmon and trout also have tolerance for temporary oxygen reduction; even though they are not as tough as the crucian carp, still their tolerance for low oxygen levels is also good. Although, they aren’t adapted to face the loss of oxygen that comes with extremely hot seasons. Hence, not all fishes need to come out of the water for air.

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Why Does My Fish Come Up For Air?

The habitat of household pets needs to be cleaned all the time; and this is also applies to fish pets. In the previous paragraphs, we were made to understand that fishes come out only when the content of oxygen in the water is significantly reduced. However, as a fish pet owner, why your fish is coming up for air should be a thing of great concern because it could let you know what you are doing wrong. Firstly, it is crucial to consider factors that can reduce the tank’s oxygen content; when the water is so cloudy for whatever reason, it can preempt the fish to come up for air. Also, when the feed is excessive on the fishbowl’s surface, the fish would not swim in the water comfortably because of the shortage of oxygen. This is why it is essential to feed the fish in bits, so you don’t end up making the fish stay afloat. It is also vital to keep the fish bowl’s water clean to allow the fish to have the required oxygen content it needs. If you stay in a really hot area or experience a hot season, you will find your fish swimming at the surface of the water because it is trying to get air to make up for the reduced oxygen in the water. This should not be a thing of concern as a fish owner because it is a normal thing for fishes to survive.

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How Do You Know A Fish Is Gasping For Air?

It is not hard to know if a fish is gasping for air and cannot breathe. The fish would usually be at the water’s surface, making excess bubbles, even at the surface of the water at the same time, swimming excessively in weird patterns. The fish might gasp due to several reasons, from poor hygiene to lack of oxygen. Gasping could also be a sign of stress in fishes; this makes it essential to know what is causing your fish to gasp for air. A fish gasping should not be confused when a fish is basking or just swimming up to get oxygen. Therefore, it is vital to act as quickly as possible if you notice that the fish is gasping and not just swimming afloat or on the surface.

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Do Fish Suffocate In Air?

When the oxygen levels in water are too high, it can be very harmful to the fish. As the saying goes, moderation in everything makes everything okay. When using artificial oxygen in the water tank, it is essential to use it in moderation so it doesn’t end up suffocating the fish. Using coarse fish as a key study, when excess oxygen is used in its fish pond or fish tank, it can cause a critical situation, which might become a medical emergency. However, a fish cannot suffocate in the air just because it is outside water; it can only die of dehydration. Fishes need air, too, just like us, so it wouldn’t suffocate if it is in the air, but it surely will if the oxygen in the fish tank is in excess.

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Signs Of Too Much Oxygen In A Fish Tank

Oxygen is a gas, which cannot be seen. When combined with water, it is not noticed either. However, when the oxygen in the fish tank is excessive, it will indeed show signs. If oxygen is too much in the fish tank, it would be made manifest in just one way- excessive bubbles. The bubbles result from outgassing from pressurized water. When the gas (oxygen) in the water exceeds the water, the water tries to eliminate it in the outgassing process. This process is where the gases are leaving the water tank; there are lots of bubbles to show its sign of leaving. There is no situation where anyone would not know if the oxygen in the fish tank is excessive. 

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How Much Oxygen Do Fishes Need?

The age-long question that most fish lovers, fish owners, and fish owning enthusiasts are very curious about, “how much oxygen do fishes need?”. We have to be informed that the moderate oxygen fishes need to survive cannot be determined easily. The required oxygen concentration of a fish tank is different in each species of fish. There are different factors to consider when the amount of oxygen needed by fish is being discussed. Factors like size of the fish, type of the fish, the habitat of the fish, species of the fish, the temperature of the water, degree of physical activity, age of the fish, time since feeding, and so many other factors to consider when you want to know the amount of oxygen, needed by the fish. 200 and 500 mg oxygen/kg fish/hour is the average consumption rate of oxygen for an adult fish.

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On the other hand, the oxygen needed of smaller fishes is not compared to bigger fishes’ needs. Study shows that smaller fishes need more oxygen than bigger fishes. In small fishes, oxygen need can be up to 1050mg oxygen/kg fish/hour. The amount of oxygen needed by fishes is also dependent on temperature. The amount of oxygen is very much dependent on the temperature of the fish tank. When the temperature is high, fishes tend to need more oxygen than usual, so they come to the surface during high temperatures. The dissolved oxygen need of cold-water fish is different from that of warm water fish. Coldwater fish survive at a concentration of 2.5 to 3.5 mg/L, while friendly water fish can survive as low as 1.0m/L. It does not matter the type of fish in question; its concentration should not be allowed to fall below 80mmHg.

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Why Does My Goldfish Stay At The Top Of The Tank?

A goldfish would stay at the top of the tank because it is not getting sufficient oxygen from the water. A goldfish staying at the top of the tank is no cause for alarm; it just wants to breathe properly. You could also help it by removing the impurities in the water. Also, when the feed put at the top of the fish tank is excessive, it can also serve as a type of pollution that can restrict the amount of oxygen available for the fish’s use. Furthermore, the fish tank must be cleaned periodically to avoid blue,-green algae and spirogyra growing, thereby sharing the oxygen meant for the fish and also polluting the water. It is essential to remove anything causing the fish’s discomfort so that the fish can swim comfortably without staying afloat because of a lack of oxygen. A fish stays at the top of the tank so that it can respire without any issues. The fish would come to the top of the tank during the hot seasons to get the oxygen depleted from the water during evaporation.

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Why Is My Fish At The Top Of The Tank Gasping For Air?

As human beings, when things do not go the way we want them to, or we are burdened with lots of activities, we can become stressed about the way things are going; this situation is not different in fishes. A fish will only gasp for air at the top of the tank because it is stressed out. There are many things that could make a fish stressed out. Examples of situations that can make a fish stressed out are; troubles with other fishes, lack of tank and water hygiene, presence of chemicals, and improper diet. In daily human life, not everyone can stay together without having issues; it is the same in fishes. Notice how we get stressed when we keep having issues with the same person every time? That is how fishes get stressed when they are kept with another fish that it does not get along with. Putting too many fishes in a bowl can also make your fish gasp for air because fishes also love their privacy or love to hide for fun. Also, lack of tank and water hygiene can cause the fish to gasp for air. When the water in the fish tank is not maintained, impurities like ammonia and nitrogen, coupled with low oxygen levels, can make the fish stressed. When it is discovered that the impurities are more than the oxygen volume, aeration should remove impurities like carbon dioxide from the water. The presence of chemicals can also be stressful to fishes. Although not just stressful, to the health of the fishes. Lastly, giving a fish an inappropriate feed can also cause it to swim to the surface and gasp. When a fish is gasping for air, it should not be taken lightly. You should either bring a professional to test the water or to check if the fish is ill.

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How To Make Oxygen For Fish At Home

In case the oxygen level of your home aquarium, fishbowl, or fish tank is reduced, there are several ways to restore it to the original oxygen concentration, which is suitable for the fish. These ways are a “do it yourself” kind of practice, and it does not involve lots of processes. The main types of tank oxygenation are manual oxygenation, battery-powered oxygenation, and electronic oxygenation. Doing manual oxygenation is pretty much straightforward. A cup is to be filled with clean water and poured at a height higher than the tank so that the water can pick up oxygen on its path as it travels into the tank. This is the easiest method of fish tank oxygenation. However, manual oxygenation is usually the second option of oxygenation; there is no power supply to use the automated one. The second option is because oxygenation is never accurate when it is used. Other impurities like carbon and nitrogen in the air might also accompany the water. Battery-powered air pumps do the battery-powered oxygenation. The pump is put into the fish tank to oxygenate the tank; it pumps air into the tank directly, thereby supplying the tank with oxygen. Although, most times, in cases where the tank is really big and deep, this battery-powered pump might not run deep to oxygenate the tank’s depths. The best part of using battery pumps is that it charges with AC when there is a power supply and keeps functioning even when the power fails. It uses its inbuilt battery to function in the case of power failure. The last type of oxygenation is done by professionals, so it would not be talked about.

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In conclusion, a fish would swim at the top of its tank if the condition it’s put in isn’t favorable; that is, it is not able to get oxygen to produce the energy it needs for its routine. 

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There is a difference between a fish staying afloat when getting atmospheric oxygen and when it’s gasping because of stress.

Hazel Buckley
Hazel Buckley

About Hazel Buckley
Hazel is an animal enthusiast and educator who grew up on a farm which her parents owned in Ingogo, KwaZulu-Natal, South Africa.  The farm was situated right under the Majuba Mountains - the site where the Anglo-Boer War was fought. 

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