The south and north poles are the regions of the planet's surface that receive the least sunlight. This causes immense layers of ice to cover the Arctic (to the north of the planet) and Antarctic (to the south). For this reason, temperatures at the poles can reach minus 40°C. This makes the environment very extreme and, at first glance, few organisms could live there. However, it turns out thatmany polar animals inhabit these regions and have developed strategies to combat the extreme cold.

(Image of Wolfgang Vogt by Pixabay)

You may wonder what has caused animals to inhabit such an extreme environment. The answer is quite simple: food. What happens is that ocean currents move the ocean floor in the regions closest to the poles. This causes nutrients that are deposited on the ocean floor to rise to the surface. All this food allows microscopic photosynthesizing algae(phytoplankton) grow exponentially. Thus zooplankton can also develop and serve as food for fish and other larger animals, such as krill.

In any case, the secret of survival in the frozen lands of Antarctica is thermal insulation. Just as humans wear several layers of clothing to prevent heat loss, polar animals also wear several layers of thermal insulation - which are - of course - not clothing. It turns out that many animals such as polar bears and seals have large reserves of fat. TheLipids are molecules that reduce heat transmission, which keeps the animals' bodies warm for longer. Furthermore, the fur and feathers of polar animals create a layer of air between the environment and the animal's body. The air also acts as a thermal insulator, which further helps reduce heat transmission.

Endothermic and ectothermic polar animals

Most of the animals that inhabit the Arctic or Antarctic are birds or mammals. This is because these animals are endothermic, that is, they use part of their metabolism to heat their bodies. This is because the burning of food naturally produces heat. This characteristic requires very caloric food, precisely to maintain the metabolism heating the body. Thus bears, seals and birdsmarine life can survive in these regions.

(Image by Mikkel Wejdemann by Pixabay)

On the other hand, ectothermic animals have more difficulty surviving in cold environments. This is because ectothermic animals do not produce their own heat and rely on the temperature of the environment. Thus, when the temperature drops too low the animal may freeze. Therefore, the largest land animal inhabiting polar regions is a 13mm insect. However, many polar fish haveanti-freeze molecules in their bodies. So these animals can survive in the deep waters of the coldest regions of the planet.