How Do Frogs Breathe Underwater? (Amazing Technique)

Frogs live all over the world except for Antarctica.

They prefer habitats that offer both dry land and plenty of water or humidity, because they’re amphibious. They breathe through their lungs on dry land, but they also spend a lot of time in the water.

Since they breathe through their lungs, how is it possible for frogs to breathe underwater without gills?

Frogs breathe through their skin when they’re underwater. It’s important for their skin to be moist at all times to absorb oxygen, even on land. They can spend a long time in the water if the oxygen levels are right, including when hibernating. Frogs also have gills when they’re tadpoles, so they stay underwater most of the time when young.

Frogs Breathe Through Their Skin

All frogs are amphibians; this means that they can live on land but also need a moist environment to live. This is because frogs breathe through their skin as well as their lungs.

Breathing through the skin is called “cutaneous respiration” or “cutaneous gas exchange.”

In frogs, it requires a thin epidermis (outer skin layer) which can be very sensitive. Too much sun can damage their skin cells, while too much wind dries their skin out.

Living near water lets them achieve the right balance of moisture for their bodies to function properly.

Not All Frogs Are Aquatic

Of course, not every frog spends its time in rivers and ponds. There are several species of terrestrial frogs as well, such as tree frogs.

Most tree frogs are not great swimmers. Instead, they have special, claw-like toe bones as well as toe pads. Some even have extra bones in their toes or special bone structure.

These features all help tree frogs climb on trees, leaves, and branches. Although they spend more time on land, these terrestrial frogs still need to keep their skin moist.

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They’ll stay near water sources, when possible, while those in rainforests rely on the humidity to help keep them wet.

There’s even some species, like the waxy monkey frog, that secretes a waxy substance from its skin. They use their legs to rub the wax all over its body to keep its skin from drying out.

How Long Can Frogs Stay Underwater?

Although their skin allows them to breathe underwater, there is a limit to how long frogs can stay there. Their skin can only handle so much gas exchange.

On top of that, there has to be enough oxygen in the environment in the first place.

In most species, the skin handles the elimination of carbon dioxide from the frog’s body. The lungs often take on most of the oxygen intake. Before they dive for long periods of time, frogs have to intake air with their lungs.

Then, they’re able to hold their breath while also taking in oxygen from the water through their skin. But it’s not clear exactly how long a frog can stay beneath the water before coming up for air.

There’s a common idea that frogs can stay underwater for between four and seven hours. However, there is no concrete data to show this is the case.

It’s possible that frogs could stay underwater indefinitely if the water has enough oxygen for them to absorb.

However, there are many factors that contribute to a frog breaching the surface, not just the oxygen levels. Frogs also need to come to the surface for food, mating, and protection from predators.

The exception to this is hibernation.

Frogs Can Hibernate Underwater

Because frogs are cold-blooded, they rely on external factors to regulate their body temperatures.

Cold winters could be deadly for them if they couldn’t hibernate. Hibernation is the process of slowing down an animal’s metabolism.

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Drastic changes in temperature would otherwise deprive frogs of food and energy. By hibernating, they reduce their energy needs, which also reduces their oxygen requirements.

Even so, they still need more oxygen than other aquatic animals like turtles. Some turtles bury in the mud to hibernate, but this would cover up too much of a frog’s skin.

Since they need their skin to breathe underwater, most frogs sit on top of the mud. They may bury parts of their bodies, but they won’t burrow all the way.

In fact, frogs will sometimes swim around during hibernation to ensure they keep their oxygen levels steady.

But what about the frogs that are even less aquatic, like tree frogs? These species will burrow down into leaves or find rock and tree crevices in which to sleep.

This may not seem like much protection against the cold, and it’s really not. Frogs supplement their burrowing spots with high levels of glucose in their blood.

This acts as an antifreeze that stops their vital organs from freezing, even as the rest of their bodies do.

The frog’s heart stops beating, and they stop breathing altogether thanks to the combination of antifreeze and slowed metabolisms. Then, when the weather warms, so do the frogs, and their metabolism speeds up again.

Can Frogs Drown?

It is possible for a frog to drown even though they’re amphibious. They have lungs just like mammals, and lungs can’t function with water in them. Skin breathing can also only give them so much air.

If its lungs were to fill with water and there wasn’t enough oxygen around them, a frog could drown.

This can especially occur in man-made areas of water, such as backyard ponds. If the edges of the banks are too steep, frogs, especially young froglets, may have difficulty leaving the water.

Eventually, their bodies will absorb all of the oxygen from the water, rendering their cutaneous respiration useless. If they’re unable to leave the water, which no longer contains enough oxygen, they’ll drown, just like a human would. 

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Baby Frogs Have Gills

We often connect breathing underwater to having gills. While adult frogs do not have gills, they are born with them.

First, frogs begin as eggs; some species, like bullfrogs, can lay as many as 20,000 eggs at a time.

Then, the eggs hatch into a tadpole, or pollywog. Tadpoles are creatures with small, round heads and long tails; at this point, they have no arms or legs.

They do have gills, though, and most species stay in the water the entire time during their tadpole stage.

As they progress into the froglet or young frog stage, these gills begin to regress. This is the stage where their lungs start to form. As such, they can begin spending more time out of the water until they’re full adult frogs.

In Conclusion

Frogs are very adaptable animals, living in different habitats all over the world. They have two different methods of breathing: through their lungs and through their skin.

Frogs can breathe underwater because their skin can absorb oxygen from the water around them. However, there has to be enough oxygen in the water.

As they breathe oxygen in, they push carbon dioxide out; eventually, the oxygen levels will become too low for skin breathing. Frogs have to swim to a new area or head to land and breathe with their lungs.

As tadpoles, frogs breathe through gills which recede as they become adults, giving way to lungs and cutaneous respiration.

This double respiration system allows them to traverse land and water, but it does come at a price. A frog’s skin must remain moist for it to be able to breathe properly. So, frogs have to have adequate water sources or humidity in their environments.

James Ball

James has had a lifelong passion for animals and nature, tracing back to his childhood where he first began fostering intimate knowledge and connection with pet frogs and snakes. He has since honed this interest into a career as a trained Wildlife Biologist, specializing in Biogeography, sustainability and conservation. In addition to his professional pursuits, James maintains an active lifestyle, regularly indulging in outdoor activities such as hiking, and musical pursuits like playing piano and swimming.

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