Can Arowanas Live Without Oxygen

Arowanas are large elongated fish with an upward-facing mouth. The mouth is useful in catching prey at the surface of the water or above the Arowana. They come in different colors that grace the tank alongside other tankmates.

Arowanas can thrive in waters with less oxygen as an advantage over other fishes and avoid prey. Arowanas can’t live without oxygen; they can only survive with little oxygen. They can also breathe in air from the surface of the water.

Can Arowanas Live Without Oxygen

Breathing Mechanism of Arowana Fish

Arowanas exhibit an amazing breathing ability. Aside from breathing in oxygenated water like every other fish, there are also other Arowanas that breathe in oxygen. They breathe in oxygen in the air by coming to the water’s surface to take in air.

You might be surprised at this and doubt if it is possible. Yes, Arowanas may breathe in the air because they are not the only fish to breathe oxygen. We will be checking out two ways Arowanas can breathe oxygen.

The first way is the very common way fish breathe. The Arowanas respire with the help of their gills. Arowanas have gills at the side of their head for respiration.

These gills are made of feather-like tissues called gill filaments. The gill filaments of the fish provide a large surface area for the exchange of gases. The large surface area is essential in fishes because water contains little dissolved oxygen, so the fish will take in much water to get enough oxygen.

During respiration, Arowanas take oxygenated water through their mouth and pass it over their gills. When the water passes through the gill filaments, the capillary network’s blood takes up the oxygen. At the same time, the circulatory system distributes it to the needed part of the body.

Another way Arowanas respire is by breathing in air and making use of the oxygen. It is possible because Arowanas are facultative breathers.  Arowanas can breathe oxygen from air by sucking air into their swim bladder. They have their swim bladder lined with capillaries that are similar to lung tissues. These capillaries obtain the oxygen in the air and dissolve it into the blood. The dissolved blood is then transported to various parts of the fish’s body.

Interesting Facts about Arowana Fish

Arowanas are interesting freshwater fishes that live in a variety of habitats. They possess a lot of fascinating features to enable them to thrive in their various habitats. Here are some fascinating facts about Arowanas.

  • Mouth Brooders: It is an amazing fact that Arowanas are paternal mouthbrooders. Paternal mouthbrooders mean the male takes care of the child before and after hatching. After the female lays the egg and fertilization occurs, the male Arowana takes the egg into its mouth to incubate them for months. During the incubation period, the male Arowana does not eat anything. After the eggs hatch, the male still keeps the small fishes in its mouth because the fishes can’t swim on their own at this stage. He keeps the egg in its mouth until the fishes can do well on their own.
  • Bony tongue: Unlike other fishes, the Arowanas have a bony tongue. You can also find some of their teeth on their tongue. They have teeth at the bottom of their mouth and also at the roof of their mouth. Arowanas have a pair of barbels at their mouth. These barbels serve as sensors for the fish. The shape of their mouth also allows them to feed at the surface, acting like a drawbridge.
  • Facultative air breather: This feature is an amazing characteristic of the Arowanas. The fish can survive in waters with low oxygen because of their facultative ability. The Arowanas can survive in water with little oxygen because they can use the oxygen in the air. The fishes have a swim bladder lined with capillaries that is similar to the lung tissues. This feature gives supplemental oxygen in case there isn’t enough dissolved oxygen in the water. It gives the Arowana an advantage over other fishes.

Feeding Your Arowana Fish

You have to feed your Arowana regularly and adequately. All living animals need to feed. You shouldn’t just feed your Arowana but feed them with a nutritious and balanced diet.

Feed your Arowana regularly. At the juvenile stage, Arowanas grow rapidly, thus needing more food and energy at this stage. Feed them twice a day with high-quality food to keep up with their fast growth.

As they grow older, their metabolic rate reduces, thus using lesser energy and consuming lesser food. At this stage, you can feed the fishes once in a day. Don’t worry about overfeeding because Arowanas will stop eating once they are filled. You should make sure you remove uneaten food from the tank so as not to increase the ammonia level in the tank.

Arowanas grow faster when you feed them with quality and adequate food. Here are some food you should feed your Arowanas;

  • Pellets: Pellets are a floating type of food. It is a suitable type of food for Arowanas because Arowanas are surface feeders. It is also rich in protein and fats.
  • Flakes: Flakes are only suitable for juveniles because adult Arowanas won’t take flakes. Flakes are rich in fiber and low on carbs. They are also suitable for feeding Arowanas.
  • Live foods: Arowanas are omnivorous fishes, so they won’t hesitate to eat live foods. Live foods are also high in protein and fats. Make sure that live foods are not infected and are suitable for consumption.
  • Vegetables: Vegetables are highly nutritious and rich in vitamins and minerals. Feed them to your Arowanas. You can also feed them green plants like water weeds, algae, etc.


Arowanas can live in water with low oxygen, but they can’t live without oxygen. They can make use of oxygen in the air when there is limited oxygen in the water. Every animal needs oxygen to survive, and Arowanas are no exception. Provide adequate conditions for your Arowana, and you are sure to get a good result.

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