Why Can Fish But Not Reptiles Live In Polar Regions?

It is indeed very interesting that no reptiles exist in the polar region. All reptiles are generally cold-blooded, meaning their body temperatures can adjust to whatever temperature in their environment. On the contrary, fish are not all cold-blooded, so it triggers the curiosity of most people on why they can survive in Polar Regions.

Why can fish but not reptiles live in polar regions? Fish can live and survive in polar regions because they undertake physiological and biochemical attributes to adapt with the cold weather. Reptiles are also not used in producing heat, yet only one reptile can be exempted from that rule.

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Check out below why fish live in the cold area of the Polar Regions while reptiles can’t. After reading the entire article, you will have a complete understanding of what capabilities are possessed by fish to be able to live in Polar regions.

Fish Capabilities

Fishes are often underestimated, yet they have special capacities to survive in cold waters despite the changes happening in their natural habitat.

Physiological and Biochemical Attributes

Fishes, though mostly cold-blooded, have large adjustment temperature capabilities towards its environment. At a certain point, their bodies produce antifreeze molecules called glycoprotein to minimize their bodies’ freezing points.

Oxygen Is Trapped Below

In colder seasons, even when the lakes and rivers are starting to turn into ice, yet there are still fishes that can be managed to survive. One reason is beneath the thick layer of ice. The oxygen is trapped, thus making it more possible for the fish to live normally and comfortably below.

The Water Temperature Changes

The entire body system doesn’t form into ice, but only the top part of the water. Beneath, the temperature below keeps on expanding from 4 °C to 100 °C. Even though the temperature change happens, it doesn’t occur overnight, and it takes a long process. Below 30 meters, the temperature is very stable for the fish to handle.

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It may be intriguing, but listed below are a few points why reptiles don’t survive in the cold waters.

Reptiles Are Not Heat Producers

Although there may be endless possibilities that they can develop the capability to adapt easily during temperature changes in the future, yet now, reptiles are too cold-blooded not to produce any heat. Their temperature would often rely based on the heat sources of their environment, meaning they are hot when it’s hot and cold when it’s cold.

A Reptile That Is Exempted To The Rule

There’s only one particular reptile that can survive in cold regions called the garter snake, which can tolerate -5°C without freezing. However, if the temperature goes below than -5°C, their body fluids would turn into ice.


As a conclusion, that is the beauty of nature. Even though there are no polar region reptiles, there are still other animals that can do so. Each of them is equally beautiful and unique, with different timelines and purposes.