You've probably heard of warm blooded animals and cold-blooded animals. AND endothermic animals and ectothermic animals, have you heard? Do you know the difference between them? Let's learn?
In the period when the animals started to be classified, they were divided into warm blooded animals and cold-blooded animals. In the group of warm-blooded animals, the birds and the mammals, in the group of cold-blooded animals, the reptiles, amphibians, a most fish and the invertebrate animals. Today the term warm-blooded animals has been replaced by endothermic animals and the term cold-blooded animals replaced for ectothermic animals. So now we say that birds and mammals are endothermic animals, and reptiles, amphibians, some fish and invertebrates are ectothermic animals.
THE endothermia and the ectothermy are mechanisms adopted by animals to control body temperature, what we call thermoregulatory mechanisms. The animals endothermal raise the body temperature and keep it constant from mechanisms internal, that is, the animal's own metabolism can control its temperature. the animals ectothermal are not able to regulate body temperature with internal mechanisms, so they need to sources external of heat to raise and maintain your body temperature constant. These animals get heat from the environment (external environment), usually with the sun exposure or in contact with hot surfaces, like rocks.
That's why mammals can stay for long periods without being exposed to the sun. Reptiles and amphibians, for example, cannot. Likewise, have you ever heard of reptiles living in very cold regions like Antarctica? Probably not, as they are unable to survive in these environments as they need to external sources of heat and your body temperature varies according to the environment (environment external). However, birds and mammals are found in cold regions as they do not depend on external heat sources to control their body temperature.
You've probably seen a lizard, snake or alligator, even in a film or documentary, “taking the sun”, right? Now we can understand why.
Reptiles need external heat sources to raise their body temperature, so it is common to see these animals exposed to the sun
Knowing this, we can understand why reptiles are not found in very cold regions. Low temperatures do not allow these animals to survive, as they need external sources of heat and also because their body temperature varies according to the environment. Mammals and birds, on the other hand, which have internal mechanisms for controlling body temperature, can be found in cold regions.
By Flávia Figueiredo
Graduated in Biology
