Endotherms vs Ectotherms PDF

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Summary

Endotherms vs Ectotherms comparisons...

Description

Compare and contrast endotherm and ectotherm thermoregulation, using examples when appropriate.

All animals need to regulate their body temperature within a certain range, ectotherms rely mainly (however not always exclusively) on external heat sources, whereas endotherms use methods of internally generating heat. Endotherms regulate their own body temperature through metabolic processes and tend to maintain a small range of core temperature since they are homeotherms, heat is generally produced during normal metabolic activity however there are additional processes that take place if the core temperature of the individual moves outside of the small range. For example going below the ideal core temperature range would lead to shivering in many endotherms. However, going over the ideal temperature range can lead to a variety of responses depending on the species of endotherm, for example members of the Canidae family begin to pant as opposed to humans who resort to sweating. Ectotherms on the other hand do not have such a small range of ideal core temperature as they are poikilotherms and their internal temperature varies greatly depending on external sources. This means they tend to be found where the ambient temperature is predictable and constant year round, such as the tropics. Most ectotherms have developed behavioural patterns that act as thermoregulation mechanisms, for example basking in the sun to increase body temperature or laying in the shade to reduce body temperature. Endotherm thermoregulation is energy consuming, and as a result of that most endotherms have significantly faster metabolisms than ectotherms. Maintaining high metabolisms mean endotherms must consume more food and on a more frequent basis than that of an ectotherm. For example, a deer may graze everyday for a door portion of the day, whereas an anaconda that has a similar body weight may eat as infrequently as once a month. It is also important to note that the further away the ambient temperature is from an individual's ideal core temperature, the more energy that is consumed to maintain it. This is clearly a disadvantage for endothermic regulation. Ectotherms have developed many behaviours and phenotypic traits that are not needed/seen in homeothermic endotherms, these act as behavioural and physiological thermoregulation mechanisms. Such as scales, basking behaviours, skin colour or body contours....