How Do Frogs Breathe?

The frog is a fascinating amphibian with unique features and traits. One aspect that may be intriguing and questionable to humans is how frogs breathe, especially underwater or during hibernation.

Frogs can breathe using four respiratory methods including through their skin, lungs, nostrils, or mouth lining. The type of respiration used will vary depending on where the frog is located. Before metamorphosis into an adult frog, tadpoles breathe through their gills.

If you have ever been curious about the way a frog breathes, keep reading. Below, you will find interesting information regarding the ways a frog breathes, as well as when and why they may choose a certain type of breathing.

There are four different ways a frog can breathe using different parts of its body including through its skin, lungs, nostrils, and lining of its mouth. 

Frogs Can Breathe Through Their Skin

Much like other amphibians, a frog can breathe through its skin through a process known as cutaneous respiration. Breathing through the skin is possible due to the frog’s thin skin that contains an immense amount of blood vessels.

During the breathing process, oxygen is diffused through the thin membranous tissue of the skin and absorbed into the blood vessels. The same process is used to release carbon dioxide from the frog’s body. The action is further encouraged thanks to the mucus coating on the outer layer of the frog (CTNF).

Since the frog will find itself in oxygen-rich waters or under the soil, it cannot rely on its lungs to breathe in the air during hibernation. Frogs will likely use the cutaneous respiration method during the winter months when they hibernate.

Frogs Can Breathe Through Their Lungs

Frogs will only breathe through their lungs when absolutely necessary. This is because a frog’s lungs are poorly developed and are not substantial enough to handle day-to-day interactions. Not only that, but lungs only start to form once the frog is a froglet (young frog).

The process for a frog breathing using its lungs is somewhat similar to other mammals, including humans. Frogs will take air in through the nostrils, which is distributed into the lungs. There are some frogs that do not have lungs to help them dive further.

Frogs Can Breathe Through Their Nostrils

However, frogs do not have ribs or a diaphragm to help store the air. Instead, a frog will simultaneously use its mouth and nostrils to take in oxygen and release carbon monoxide.

To do so, the frog will lower its mouth to expand its throat. At the same time, the nostrils open to accept oxygen. As the nostrils and mouth are close, the oxygen is forced into the lungs.

Frogs Can Breathe Through Their Mouth

The last option for breathing for a frog is through their mouth. A frog’s mouth contains a special, moist lining that is extremely permeable. When a frog is not entirely submerged in water, it can rely on its mouth to take in oxygen and release carbon monoxide.

Learn more about frog anatomy in this detailed guide on our blog.

Do Frogs Breathe Through Gills?

During the tadpole stage, the frog breathes uses its gills to breathe like a fish. These external gills take in oxygen as water passes over them. But a frog’s breathing will not rely on gills for its entire life.

Through the process of metamorphosis, a tadpole will begin to absorb their gills as they grow older. As a tadpole becomes a froglet, the gills become a part of the internal anatomy, and lungs develop.

However, although an adult frog has lungs, they are not developed enough to handle day-to-day breathing processes for the frog. This is why adult frogs will rely mostly on their skin and mouth to breathe.

When Do Frogs Lose Their Gills?

The tadpole starts to lose its gills near the end of its transformation as a tadpole and at the beginning of its transformation into a froglet at around 14 to 19 weeks of age.

The froglet’s former gills which were required to breathe are slowly and steadily absorbed as the frog develops lungs to breathe on land and becomes a full-fledged adult. This can take around 6 to 9 weeks depending on the species.

Can Frogs Breathe Underwater?

Adult frogs cannot breathe underwater because they have lungs and can down if they are filled with water. However, during hibernation, frogs slow down their heart rate and primarily breathe through their skin absorbing oxygen in the water around them.

Frogs can remain underwater for short periods of time to hide or swim, but cannot rely on their lungs to breathe beneath water. Tadpoles however, have gills that allow them to thrive underwater, but prevent them from living on land. It’s only once the frog reaches the froglet stage that it begins to lose its gills, develop lungs and can live on land.

How Long Can Frogs Remain Underwater?

As a general rule, frogs can live 4 to 5 months in underwater or in mud when they are hibernating. During the Summer, they can spend hours submerged with their head above water breathing through their nostrils and skin. Tadpoles spend 14 to 19 weeks underwater until they can live on land as froglets.

This ability stems back from the frog’s uniquely designed body and respiratory system. Since the frog uses its skin and mouth to breathe in and out of the water, it can easily stay hydrated and oxygenized for long periods of time.

Can Frogs Drown?

Frogs can drown due to a few different reasons:

  • Their lungs filled with water
  • There is not enough oxygen in the water
  • The water is polluted or contains too much nitrate
  • Their skin is dried out to the point it cannot absorb water or oxygen

For these reasons, the frog needs to find a safe location with clean oxygenated water to live. It should not be without moisture for excessive periods either, or it will essentially dry out and be unable to breathe.

Learn more about why frogs may drown in this article on our site.

Do Frogs Breathe While They Are Hibernating?

Frogs breathe while they hibernating, although they slow down their respiratory system and primarily absorb oxygen and release carbon monoxide through their skin

As a general rule, a frog has three different methods for breathing after morphing from a tadpole. As a tadpole, it utilized gills to survive. As an adult frog, it relies on its skin the most for breathing, especially while underwater. However, it can also use its lungs, nostrils, and mouth to receive oxygen and expel carbon monoxide.

Learn about what sounds frogs make and identify frogs you find with the articles on our site!

Other Questions Related to How Frogs Breathe

Do Toads Breathe Through Their Skin? Toads breathe through their skin and can also breathe through their lungs and nostrils. As tadpoles, toads breathe through their gills which they lose as toadlets.

How do Frogs Breathe? Frogs can breathe through their skin, lungs, nostrils, or mouth lining and their choice depends on where the frog is located. As tadpoles, frogs breathe through their gills.

Sources

Daily Sentinel

Canal River Trust

Chesne, Corinne. La Grenouille. Artémis éd., 2009.

Parsons, Harry. L’univers Des Grenouilles: Amphibiens Poseurs. Éditions Du Trécarré, 2000. 

Grenouilles, Crapauds Et Rainettes: Morphologie, Comportement, Alimentation Et Reproduction …, by S. Caratozzolo, De Vecchi, 2008.