Frogs can survive being frozen during winter thanks to a process called cryopreservation. Their bodies produce antifreeze substances that protect them from the harmful effects of freezing, allowing them to maintain their survival despite extremely low temperatures.
These amphibians have developed incredible abilities to endure extreme conditions. Among their tricks, they have particularly permeable skin that allows them to quickly absorb water and oxygen, even when everything slows down during freezing. Their hearts nearly stop beating, their breathing ceases, and yet, they remain alive in the form of little amphibian ice cubes. They can even accumulate special reserves of glycogen in their liver to prepare for the rigors of winter. This extremely slowed metabolism drastically reduces their need for oxygen and energy, which explains their impressive survival even in the most intense cold.
When the frog starts to freeze, its body quickly detects the formation of the first ice crystals. At this moment, it reacts by massively producing glucose released into the blood, a sugar playing a fundamental role as a natural antifreeze. This glucose spreads into its cells to prevent them from freezing completely or being pierced by sharp ice crystals, thus significantly reducing cellular damage. In parallel, the frog also uses other substances like glycerol or urea, compounds that also act as cryoprotectants. These molecules strongly limit the formation of sharp crystals in living tissues, ensuring optimal cellular survival even during prolonged freezing. Thanks to this mechanism, the heart and respiration completely stop during the freezing period, before quietly resuming their activity when thawing occurs.
When a frog starts to freeze, it is primarily its limbs and skin that undergo freezing. It stops breathing and its heart almost ceases all activity, putting it in a state of suspended life. Then, ice gradually forms outside its cells, causing controlled dehydration that reduces internal damage. Meanwhile, the organism produces large amounts of protective substances like glucose, which acts like a natural antifreeze. In spring, the warming causes this ice to slowly melt, allowing its heart and metabolism to gently restart, and its blood circulation to return to normal. After just a few hours, it regains all of its functions and resumes as if nothing had happened.
Sugars like glucose and glycogen play a key role in frogs that can remain frozen all winter without worry. In fact, these sugars act as a kind of natural antifreeze. As winter approaches and temperatures begin to drop, frogs quickly convert their glycogen reserves into glucose. This glucose then diffuses throughout their cells. Why? Because it prevents the water within their cells from forming sharp ice crystals that could pierce or damage these cells. In other words, glucose serves as protection and limits damage during freezing and thawing, thus giving cells and organs a better chance to function normally when temperatures rise again. Not at all foolish, Mother Nature!
Among the frogs capable of surviving when frozen, the most well-known is the wood frog (Rana sylvatica), a true champion of winter. The spring peeper (Pseudacris crucifer) and the leopard frog (Lithobates pipiens) are also encountered, adapted to tolerate significantly negative temperatures. Even more impressively, the northern terrestrial frog, known as the common frog (Rana temporaria), can survive at temperatures approaching -6°C. All of these species possess exceptional biological mechanisms that protect their cells from the damage of extreme cold.
Glucose, released in large quantities during cooling, acts as a natural antifreeze in frogs, preventing the formation of ice crystals in their cells and thus avoiding fatal damage.
Did you know that after thawing, frogs show no significant decrease in their physical abilities or lifespan? This is a nearly unique feat among terrestrial vertebrates.
During freezing, the hearts of some frogs completely stop beating for several days or even weeks, then spontaneously resume their normal rhythm when they thaw!
Thanks to their extraordinary biological adaptations, some species of frogs can survive being frozen at temperatures as low as -8°C without suffering permanent damage.
During the freezing period, the vital functions of the frog slow down considerably, including its neural activity. It is therefore assumed that they do not feel pain or discomfort during this time.
Some frog species, such as the wood frog (Rana sylvatica), can survive for several weeks, even months, partially frozen during the winter. Their tolerance largely depends on the species, environmental conditions, and their internal physiology.
Frogs primarily use glucose derived from their glycogen reserves as a cryoprotective substance. This sugar acts as a natural antifreeze, protecting cells from damage caused by ice crystals.
No, only certain specific species such as the wood frog, the Arctic frog, and some species of tree frogs have the necessary physiological adaptations to tolerate partial freezing.
The main risk faced by frogs during freezing is the formation of intracellular ice crystals, which can rupture cells. However, adaptations such as the accumulation of glucose help to mitigate this damage.
When the external temperature drops, environmental signals trigger a physiological response in adapted frogs. They quickly release glucose from their glycogen reserves, primarily located in the liver, in order to protect their cells.
0% of respondents passed this quiz completely!
Question 1/5
