Fish Tank Pump

There Are Aquarium Fish That Can Do Without Oxygen

August 21, 2019

Whatever the fish were diverse, but they can not live without oxygen. This concept does not mean the absence of respiration, but the ability to live in water with low oxygen content. In nature, these are stagnant waters of marshland, rice fields, closed reservoirs. Similar conditions arise in small aquariums that are not equipped with filtration and aeration systems. Only unpretentious small fishes will approach here.

What fish can live without aeration (oxygen)

Some fish that do not need a high oxygen content in water are able to use atmospheric air for breathing due to the presence of specific organs or another method (gill labyrinth, intestinal or skin respiration).

Many fish will survive without artificial oxygen supply, but only with an open aquarium! Without access to air, fish with additional respiratory organs die. Therefore, the surface of the water should not be completely covered with plants.

Without a filter

Such are the slider or labyrinth fish, which in the course of evolution developed additional labyrinthic bone plates with folds of the mucous membrane, thanks to which they are also able to use the air for breathing in an aquarium without oxygen. Aeration for such fish is optional!

By the labyrinth include:

  • cockerels (fighting fish, betta);
  • all gourami;
  • ctenopoma;
  • Macropods (paradise fish);
  • swordtails;
  • lyalius and others.

There Are Aquarium Fish That Can Do Without Oxygen

Schooling fish require less volume per individual. Undemanding to the habitat of guppies. A flock of 6 individuals can be kept in 40-liters with several neighbors.

Once a week it is necessary to change the water and siphon the ground!

Read more:  How To Run The Aquarium For The First Time

With filter

Loachworm and tropical catfish are capable of drawing air into a particular part of the intestine. Bag-haired catfish and Clarius are used for breathing by the jabber cavity. These amazing animals can live for a long time not only without oxygen, but also without water. In nature, they thus move from one reservoir to another.

Bottom catfishes are most popular with aquarists, for example, speckled catfish. Usually they serve as “orderlies” of household ponds, eliminating food debris. But, as bottom dwellers, they contribute to raising the suspension from the bottom, muddy water. In an aquarium densely populated with catfish, filtration is necessary.

There Are Aquarium Fish That Can Do Without Oxygen

Most fish use skin breathing. In inhabitants of stagnant bodies of water with warm water, this figure can reach 80% versus the usual 10–20%. Even less demanding to aerate the young. This is soma, eels.

For fish that need a filter, but can do without aeration include:

The necessary conditions

Aquariums without filtration and aeration require more thorough care, including:

  • initially competent selection of pets, taking into account the species characteristics (aggressiveness, size, habitat conditions);
  • regular cleaning with a siphon;
  • partial water change every 2–3 days;
  • tight control of the number of inhabitants to avoid overcrowding;
  • timely thinning of the aquarium flora to prevent overgrowing of the domestic pond;
  • careful monitoring of the condition of pets for the timely identification of problems and diseases.

Fish, which necessarily need filter and oxygen

There is a confusion that barbs and goldfish can also live without a filter and oxygen, but this is not so. For them, additional equipment is necessary (filter, water pump)!

Read more:  How To Make An Air Pump For An Aquarium

Barbusy suitable for tanks of small volume, especially dwarf.

But the goldfish in small or round aquariums will live much less than the period given by nature, even with intensive care.

Lack of oxygen

No matter how unpretentious the fish are, who live without additional enrichment of water with oxygen, they can also suffer from its lack. The critical air content in the water for each type of underwater inhabitants is different.

  • rapid breathing, "bulging" gills;
  • fish swim above and swallow air;
  • even bottom fish often swallow air upstairs;
  • reduced pet activity;
  • over time, the brightness of the color decreases, resistance to disease, slows growth.

The oxygen consumption of fish in the aquarium increases after feeding, with increasing water temperature at night, especially in the presence of dense vegetation. All aquatic plants absorb oxygen in the dark.

The most effective way to save fish suffering without oxygen is to install an air-stone water pump. The air flow is dissipated, then rises to the surface, mixing water and saturating it with oxygen. In a small aquarium, the water pump may not be stationary, but temporary in order to preserve the decor. It is enough to connect it for 40 minutes per day (or if necessary) and remove it until the next time. At the same time water from the tap can not be taken! She must be defended.

If temporary measures do not help, stationary equipment is required to supply oxygen to the aquarium — a water pump and filter. The filter is needed for water purification from organic matter, the decomposition of which absorbs a significant part of oxygen. The power and type of the filter depends on the volume of the tank – for a 500-liter external filter is required, and a 50-liter is sufficiently internal.

Read more:  Vacuum Pump Do It Yourself From Water Pump


To determine which aquarium fish live without additional oxygen supply, it is enough to remember that they must have respiratory organs other than the gills, or be unpretentious. Such underwater inhabitants are quite diverse both in color and behavior. Active, accommodating guppies are also viviparous and prolific. Predatory gourami aggressively defend the territory. Among the warlike males there are very colorful individuals. A swordtails easy to pick neighbors.

Create a corner of nature at home under the power of each!