It’s well-known that frogs live both on land and in water since they begin their lives as fully aquatic tadpoles and develop into semi-aquatic adults.
But, how they manage to survive underwater leaves plenty of room for confusion.
Frog tadpoles can breathe underwater through their gills and skin. As frogets, and adult frogs, they lose their gills but can breathe underwater by absorbing oxygen from the water (cutaneous respiration). Some frog species are fully aquatic and spend the majority of their lives underwater.
Although frogs can breathe underwater for varying timeframes, there are still many influential factors to consider.
I am going to explain how frogs breathe underwater, how they use their underwater breathing skills, and their potential limitations when staying underwater over time.
Frog Tadpoles Breathe Underwater Through Gills
As tadpoles, frogs breathe through their gills.
Depending on the species, frogs become tadpoles 3 to 5 days after the frog eggs are laid.
Once they are tadpoles, have no feet, no hands, but can breathe through their skin and gills like fish.
After about 16 weeks, tadpoles have developed into froglets or toadlets (depending on the species).
At this stage of their life cycle development, they have feet and legs.
Their tail is being absorbed by their bodies and has disappeared.
At this stage, frogs have lost their gills and have developed lungs.
Once frogs have become juvenile frogs, or froglets, they can live on land outside of water thanks to their lungs.
As adults, frogs lose their gills and gain lungs, but can still breathe underwater through their skin via cutaneous respiration.
This allows frogs to be semi-aquatic and semi-terrestrial creatures.
Adult Frogs Breathe Underwater by Cutaneous Respiration
The cutaneous respiration process involves absorbing oxygen and releasing carbon dioxide through their thin membranous skin tissue.
This process allows oxygen to enter the bloodstream through diffusion, as their skin contains an immense number of blood vessels (CTNF).
Cutaneous respiration is also aided by the mucus coating on the outer layer of the frog’s skin.
Frogs can use their skin to absorb oxygen from many underwater sources, such as the water itself or moist mud at the bottom of water bodies.
I love to go looking for aquatic frogs in nature.
I often find them sitting at the edge of a pond or calm body of freshwater during the day.
They generally have their nose striking out of the water which makes them easy to find.
They spend most of the day in the shade, breathing through their nose (lungs) and skin.
Some Frogs Live Underwater
Semi-aquatic frog species, such as American Bullfrogs, Green Frogs, and Common Frogs can survive underwater for lengthened timeframes compared to toads that spend the vast majority of their adult lives on land.
Some frog species also have thinner membranes in their skin, which allows them to absorb oxygen and release carbon dioxide far more easily than other frog species.
These species would generally be able to remain underwater for longer time frames or survive in water bodies with limited oxygen content.
Other frog species have unique adaptations for survival.
For example, the critically endangered Titicaca Water Frog (in the video at the moment marked above) has incredibly wrinkled skin, which increases the total surface area for more efficient cutaneous respiration processes.
As a result, this frog can survive with far less oxygen than most frogs.
In some cases, frogs can even survive in very low-oxygenated water bodies, as they can lower their metabolic rates so that they require much less oxygen to survive.
However, frogs will need to resurface if the oxygen levels are too low underwater, where they would use their lungs and other bodily functions to absorb more oxygen on land.
The amount of time spent underwater will primarily depend on the frog species.
For example, toads generally spend far more time on land, while other species spend plenty of time on land and in water throughout their lives.
However, most frog species inevitably return to water bodies at some point for mating and laying eggs (CTNF).
Some Frogs Hibernate Underwater
Leopard Frogs, Green Frog, Mink Frog, Pickerel Frogs, Bullfrogs, and their tadpoles hibernate below freezing water.
Aquatic frogs generally sit, float, or slowly swim at the bottom of ponds.
Oxygen levels are high below 4°C or 39°F and provide a great environment for them to hibernate during Winter.
Since frogs are cold-blooded ambush predators, they do not require much energy or oxygen to stay alive.
As a result, they can lower their metabolic rates during hibernation or estivation to the point where they do not move, slow down bodily functions, and hardly breathe.
They can use cutaneous respiration to survive underwater by slowing down metabolic rates as they hibernate through winters.
Although frogs can breathe underwater, their capacity for cutaneous respiration varies depending on numerous factors.
Frogs require appropriate environmental conditions to keep the water’s oxygen levels high, and they need to enter and exit their habitat’s water bodies with ease to prevent drowning.
Frogs Can Drown Underwater
Frogs, just like any other terrestrial animal, can drown.
Frogs have lungs, despite being able to breathe through their skin as well. When these lungs fill up with water, they can drown.
Insufficient oxygen in the water makes the frog unable to absorb enough oxygen for survival.
Although frogs can breathe underwater, they will not be able to survive with no oxygen at all.
They will inevitably pass away underwater if the oxygen runs out.
Frogs need to be able to get in and out of water bodies with ease to avoid such dire outcomes, as they may drown if they are trapped underwater.
If you have a backyard frog pond, be sure it is sloped so frogs can easily exit.
How Long Can a Frog Stay Underwater?
Frogs can stay underwater up to 23 hours per day to 4 months depending on the species, their environment, the water quality, the water oxygen levels, the water temperature and their skin.
When there is a relatively low oxygen level in the water, frogs will undoubtedly have a fairly limited timeframe to remain underwater with sufficient oxygen.
Many amphibians deal with this sort of problem when attempting to remain submerged, as they often live in habitats that feature stagnant water bodies.
The water’s temperature also impacts the frog’s ability to remain underwater over time.
Colder water typically contains more oxygen (below 4°C) and helps slow down a frog’s metabolic rate.
This means that not only does the water contain more oxygen, but the frog’s bodily functions also require less oxygen.
As a result, aquatic frogs can remain submerged in colder water for longer periods of time, especially while estivating during winter.
Warmer temperatures typically speed up metabolic rates, increasing the overall demand for oxygen.
As a result, frogs dwelling in warmer waters need to resurface after a shorter timeframe to receive sufficient oxygen from the environment.
Water temperature is one of the problems climate change is posing to frogs.
More About Frogs And Water
Learn more about frogs and their interactions with aquatic environments in the specific guides on our blog below:
- How Do Frogs Breathe?
- Can Frogs Survive Saltwater?
- Will Tap Water Kill Frogs?
- Can Frogs Drown?
- Can Toads Swim?
- Can Tree Frogs Swim?
- Do Toads Like Water?
Common Questions About Frogs And Water
Do Frogs Have Gills? Frogs have gills as tadpoles, as they are fully aquatic during this developmental phase. However, frogs usually lose their gills and develop lungs as they metamorph into mature frogs. It is possible for a few frog species to retain their gills into adulthood for optimal breathing on land and underwater.
How Long Can Frogs Stay Underwater? Frogs can stay underwater up to 23 hours per day to 4 months depending on the species, their environment, the water quality, the water oxygen levels, the water temperature and their skin.
Can frogs breathe out of water? Frog tadpoles cannot breathe out of water because they do not have lungs. However, once they reach the froglet and adult frog stages of their life cycle, frogs can breathe out of water thanks to their lungs.
Can toads breathe underwater? Toad tadpoles can breathe underwater via their gills. Adult toads can breathe underwater through their skin. However, adult toads generally avoid water unless it is mating season and they need to reproduce.