If you have a fish tank, which fish can live without oxygen in the water?
You might be surprised that several species have evolved mechanisms that allow them to survive underwater.
These are the 20 fishes that have evolved mechanisms that allow them to survive in water without oxygen, and they’re all pretty incredible, which is why we’ve briefly outlined some of their features here.
1) Guppies.
Guppies are small fish naturally found in freshwater areas of the Americas. Hobbyists typically keep them as pets and for the study of genetics.
It’s a common misconception that guppies are like other fish, which need oxygen to survive.
However, they have evolved the mechanisms that allow them to breathe through their skin.
This allows them to live in aquatic habitats and even some brackish water biomes such as ponds and marshes.
2) Bettas.
Bettas are a species of freshwater fish that is native to Asia.
They’re typically kept in aquariums by hobbyists, and many people are surprised to learn that they don’t need oxygen.
Bettas breathe through their skin, which means that they’re able to survive underwater without any additional air.
3) Paradise Fish.
These fish are also sometimes sold as pets which is why you might have seen these on display even in stores that do not specialise in selling aquarium supplies.
To increase the chances of surviving underwater, which fish can live without oxygen in the fish tank, they have developed special membranes that can help them extract more oxygen from the water surrounding them.
4) Zebra Danios.
The zebra danios are freshwater fish that originates from Thailand.
As a species, they’re also fairly popular among hobbyists who keep aquariums, and many of them prefer to use this particular species instead of other types of tropical fish.
This is because their unique black stripes, and bright, colours make them exceptionally attractive and eye-catching.
5) Goldfish.
Goldfish are a group of freshwater fish found in lakes and ponds in several different parts of the world, including Russia.
The goldfish is one of the best examples of species that have evolved to live without oxygen.
This is because they can store large amounts of waste products within their flesh as well as cyanide.
These features allow them to survive underwater for extended periods of time, even without any oxygen at all.
6) Gourami.
Gouramies are one of the most commonly kept aquarium fish.
They have a varied number of species, which are all brightly coloured and easy to care for.
If you find or buy goldfish that need oxygen in the water tank, they will typically be gouramis.
7) Tetras.
Tetras are one of the most commonly kept tropical fish, and their small size makes them ideal for smaller aquariums.
They’re typically also very affordable, which is why they’re so popular among hobbyists who want to start out keeping fish tanks at home.
However, tetras don’t need oxygen to keep living underwater, as they have developed other mechanisms that allow them to survive without needing to breathe air at all.
Maintenance
In reality, smaller fish tanks require more upkeep than large ones.
While it is true that you will need to do less, essential maintenance, which includes checking water levels and adding dechlorinated water as needed, cleaning the fish tank and changing the filter and disinfectants more frequently, are all essential for any aquarium owner.
Although beginners can maintain small fish bowls, I would not suggest getting a smaller bowl if you are not prepared to do the regular maintenance required for even the smallest pets.
Temperature
Contrary to popular belief, the temperature which your fish prefers is not always necessary.
While this may be true for some larger tropical fish that can be kept at higher temperatures, which helps them survive and thrive, many cold-water species cannot handle high temperatures.
Consequently, the survival rate would be below if you were to place them in a too-warm environment.
As a result, many bowls considered 10 gallons or less usually have a thermostat that automatically adjusts the temperature according to preference, which is perfect for beginners who may not know how to regulate temperatures themselves yet.
Ammonia and Waste: The Danger of Overfeeding
One of the significant problems that plague inexperienced fish tank owners who are still getting to know their pets and understand what they like or do not like is overfeeding, which can cause a buildup of waste, which creates ammonia highly toxic and will kill fish.
As such, if you are new to fish keeping, you mustn’t feed them too much, which most pet owners find hard to do, especially when it comes to fish that they have grown fond of.
Suppose you are in doubt about whether or not you should feed your fish. In that case, you should hold off for a few days and let the food which is already in the tank go bad before providing them again, which is something which many professional breeders do as a precaution which ensures that their fish are not harmed by overfeeding which can be dangerous for all fish.
Conclusion
Guppies, bettas and paradise fish are three types of freshwater fish that can live without oxygen in a fish tank.
Zebra danios, goldfish, gourami and tetras are also some other types of water-dwelling creatures that thrive with little or no air to breathe at all.
If you’re wondering how often you need to clean your tank for these kinds of aquatic life forms, it’s not as much work since they don’t produce ammonia as most aquarium dwellers do.
However, if overfed by the owner, then there is a danger from too much waste building up in the water, which leads to toxic levels of ammonia gas being produced.
