Aquarium Fish That Do Not Need Oxygen: A Comprehensive Guide

Aquarium Fish That Do Not Need Oxygen

Aquarium enthusiasts often seek low-maintenance fish, especially those that can thrive in environments with minimal aeration. While it’s a myth that any fish can survive without oxygen entirely, certain species have adapted to low-oxygen environments. These aquarium fish that do not need oxygen in the traditional sense are fascinating creatures with unique respiratory adaptations. This article from Doshared explores the best options for such fish, providing a comprehensive guide for enthusiasts looking to diversify their aquariums.

Understanding Fish Respiration

Before delving into specific species, it’s crucial to understand how fish breathe. Most fish extract oxygen from water using their gills. However, some species have developed additional respiratory methods, allowing them to survive in low-oxygen environments. These adaptations include:

  1. Labyrinth Organs: A specialized structure that allows fish to breathe atmospheric air.
  2. Modified Gills: Certain fish can gulp air from the surface, supplementing their oxygen intake.
  3. Lungs: Some species, like the African lungfish, possess lungs for breathing air directly.

These adaptations make certain fish ideal for environments where traditional aeration might be challenging.

Top Aquarium Fish That Do Not Need Oxygen

1. Betta Fish (Betta splendens)

Betta Fish (Betta splendens): Aquarium Fish That Do Not Need Oxygen

Betta fish, known for their vivid colors and elaborate fins, are a popular choice among aquarium hobbyists. Native to Southeast Asia, they are often found in shallow, oxygen-depleted waters like rice paddies and slow-moving streams. Betta fish possess a labyrinth organ, enabling them to breathe atmospheric air. This adaptation allows them to thrive in tanks with minimal aeration.

  • Care Requirements: Bettas require a minimum of a 5-gallon tank, a stable temperature of 76-82°F, and regular water changes to maintain water quality.
  • Behavior: Males are territorial and should be housed separately or with non-aggressive tank mates.

2. Gouramis

Gouramis are another group of labyrinth fish, well-suited for low-oxygen environments. Popular species include the Dwarf Gourami (Trichogaster lalius) and the Pearl Gourami (Trichopodus leerii). These fish are known for their vibrant colors and peaceful nature.

  • Care Requirements: A 10-gallon tank is suitable for most gouramis, with a temperature range of 72-82°F. They prefer a well-planted tank with hiding spots.
  • Behavior: Gouramis are generally peaceful but can be territorial. They do well with other non-aggressive fish.

3. Paradise Fish (Macropodus opercularis)

Paradise Fish (Macropodus opercularis)

Paradise fish, native to East Asia, are known for their hardiness and ability to breathe atmospheric air via their labyrinth organ. They are strikingly beautiful, with elongated fins and vibrant coloration.

  • Care Requirements: A 20-gallon tank is ideal, with water temperatures between 68-82°F. They thrive in a planted tank with ample hiding spaces.
  • Behavior: Males can be aggressive, so careful consideration is needed when choosing tank mates.

4. African Lungfish (Protopterus spp.)

The African lungfish is a remarkable species with both gills and lungs, allowing it to survive in oxygen-depleted water by breathing air directly. These fish can even survive out of water for extended periods during droughts.

  • Care Requirements: Lungfish require large tanks (at least 75 gallons) with a secure lid to prevent escape. They need a varied diet and clean water conditions.
  • Behavior: They are generally solitary and can be aggressive, making them unsuitable for community tanks.

5. Corydoras Catfish

Corydoras Catfish

While Corydoras catfish do not possess labyrinth organs, they can gulp air from the surface, which allows them to survive in lower-oxygen environments. These bottom-dwellers are popular in community tanks due to their peaceful nature and efficient cleaning habits.

  • Care Requirements: A minimum of a 10-gallon tank is recommended, with water temperatures between 72-78°F. They thrive in groups of at least five.
  • Behavior: Corydoras are social and do well with other peaceful fish.

Benefits of Keeping Low-Oxygen Tolerant Fish

Opting for “aquarium fish that do not need oxygen” offers several benefits:

  1. Low Maintenance: These fish require less stringent aeration, making them ideal for beginners or those with less advanced aquarium setups.
  2. Versatility: They can thrive in a variety of environments, from small tanks to larger community setups.
  3. Resilience: Their ability to breathe atmospheric air or tolerate low-oxygen conditions makes them hardier and more resilient to common aquarium issues.

Setting Up a Tank for Low-Oxygen Tolerant Fish

When setting up an aquarium for fish that thrive in low-oxygen conditions, consider the following:

  1. Tank Size: Ensure the tank is appropriately sized for the species. Betta fish and small gouramis can thrive in smaller tanks, while larger species like lungfish require substantial space.
  2. Temperature Control: Maintain stable water temperatures suitable for the specific species.
  3. Water Quality: Regular water changes and a good filtration system are essential to prevent the build-up of harmful substances.
  4. Aquascaping: Provide ample hiding spaces with plants, rocks, and driftwood to create a natural and stress-free environment.
  5. Surface Access: Ensure there is easy access to the water surface, allowing fish to gulp air if needed.

Common Challenges and Solutions

While keeping “aquarium fish that do not need oxygen” can be rewarding, it comes with its challenges:

  1. Aggression: Species like Betta and Paradise fish can be aggressive. Provide ample space and carefully choose tank mates.
  2. Water Quality: Even though these fish can tolerate low oxygen, poor water quality can still be harmful. Regular maintenance is crucial.
  3. Temperature Fluctuations: Sudden changes in temperature can stress these fish. Use a reliable heater and monitor water conditions regularly.


Exploring the world of “aquarium fish that do not need oxygen” opens up exciting possibilities for aquarium enthusiasts. These fish, with their unique adaptations and resilient nature, can thrive in environments with minimal aeration, offering a captivating and low-maintenance option for both beginners and experienced hobbyists. By understanding their specific needs and creating a suitable habitat, you can enjoy the beauty and diversity these remarkable species bring to your aquarium.

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