The animals in the animal kingdom are grouped into two different categories on the basis of their ability to regulate body temperature according to a change in the external environment. Those animals that can maintain their internal body temperature despite the changing surrounding temperature are known as warm-blooded or homeothermic animals, while those animals who are unable to maintain the body temperature internally and change according to the temperature change in the surrounding environment are known as cold-blooded or poikilothermic animals.
Summary
Cold-Blooded vs Warm-Blooded
The main difference between the Warm-blooded and the cold-blooded animals is that the cold blooded are not able to maintain a constant internal body temperature as per the changing temperature of the surroundings while the warm-blooded animals can maintain their internal body temperature to a constant value even if the temperature of their surrounding environment changes. This property helps warm-blooded animals to adapt to particular temperature ranges and survive.
Cold bloodedness, also known as heterothermy, poikilothermy, or Ectothermy, Is a state in which an organism has a variable body temperature. This value of internal body temperature is slightly higher than the temperature of their surroundings. This characteristic is used to differentiate the fishes, amphibians, reptiles, and other invertebrates from birds and mammals. Since these animals depend on environmental conditions for maintaining warmth inside their body, they thrive in limited temperature ranges.
Warm bloodedness, also known as homeothermy is the ability of the organism to maintain a constant internal body temperature. This characteristic is found mainly in birds and mammals. The body mechanisms inside the bodies of these organisms counteract the effects of external temperature by increasing the production of heat and reducing the heat loss in the cold environment and decreasing the production of heat and increasing heat loss in a hot environment. And when these organisms are in neutral temperature zones, they neither lose heat nor gain heat… Thus maintaining a constant body temperature.
Comparison Table Between Cold-Blooded and Warm-Blooded
| Parameters Of Comparison | Cold Blooded | Warm Blooded |
| Definition | Cold bloodedness, also known as heterothermy, poikilothermy, or Ectothermy, Is a state in which an organism has a variable internal body temperature. | Warm bloodedness, also known as homeothermy is the ability of the organism to maintain a constant internal body temperature. |
| Source of Heat | Recieve heat from the surrounding environment | Recieve heat from the consumption of food |
| Rate of Metabolism | Metabolic rates change with changing environmental conditions but are really low | High metabolic rates that help to produce large amount of energy and heat |
| Body Temperature | Body temperature changes according to a change in the temperature of their respective surroundings. | Constant body temperature, generally ranges between 35-40°C |
| Mechanism | Basking in the sun, changing the colour of the body | Metabolic processes and mechanisms like panting, perspiration and hibernation |
| Body fat | Excess body fat may lead to death | Body fat plays an important role in temperature regulation |
| Examples | Fishes, amphibians, reptiles | Mammals and birds |
What is Cold-Blooded?
Cold bloodedness, also known as heterothermy, poikilothermy, or Ectothermy, Is a state in which an organism has a variable body temperature. This value of internal body temperature is slightly higher than the temperature of their surroundings. Since these organisms depend upon the surrounding temperature for the maintenance of their body temperature, they are found in a very limited temperature range. Their terrestrial distribution is limited with only a few exceptional cases found in a temperature range of 5-10°C and 35-40°C.
Cold-blooded animals are however able to maintain the internal body temperature to some extent by adopting physiological means such as basking in the sun. The food requirements of cold-blooded animals are very less as compared to warm-blooded animals. However, even a slight fluctuation in their body temperature may lead to a dramatic change in their internal body temperature.
Several adaptations help the cold-blooded animals to survive the changing weather conditions. As the temperature of the surrounding starts riding, some poikilotherms may dig a burrow or become dormant for that particular period. Some animals may also release heat shock proteins That prevent the denaturation of some important proteins in their body and protect them from overwhelming high temperature.
What is Warm-Blooded?
Warm bloodedness, also known as homeothermy is the ability of the organism to maintain a constant internal body temperature. This characteristic is found mainly in birds and mammals. In mammals, this internal temperature is approximately 40°C. These organisms regulate their body temperature by adapting various mechanisms that help them to retain heat in the cold surrounding, lose heat in hot surroundings, and function neutrally in a neutral environment.
Shivering is one of these mechanisms that warm-blooded animal uses to increase heat production and help them survive in the cold surrounding. Some warm-blooded animals may also use hibernation to protect themselves from the extremely cold climate. Perspiration and panting increase heat loss through the body and maintain the body temperature. Birds and mammals are homeothermic animals and hence they are found in different temperature zones. Their ability to adapt as per their surroundings makes them viable in conditions that may be fatal for cold-blooded animals. 37-41°C is the internal body temperature of humans.
Main Differences Between Cold-Blooded and Warm-blooded
- Warm-blooded animals can regulate their internal body temperature while the internal body temperature of cold-blooded animals changes according to the change in their environment.
- Cold-blooded animals change their body temperature by Ectothermy while warm-blooded animals maintain their body temperature by endothermy.
- Cold-blooded animals go through hibernation and aestivation to protect them from extreme climatic conditions while warm-blooded animals don’t need these mechanisms. Some organisms may however show hibernation.
- High energy organ systems such as the brain is absent in cold-blooded organisms while a complex organ system is found in warm-blooded organisms.
- Cold-blooded organisms may try to regulate their body temperature to some extent by basking in the sun, stretching their hands and feet while warm-blooded animals may regulate their body temperature by perspiration, panting, sweating.
- Cold-blooded animals are not found in extreme climatic conditions while warm-blooded animals survive well in extreme climatic conditions.
Conclusion
Different organisms adapt different mechanisms of survival and each of these mechanisms is important. While homeotherms or warm-blooded animals are found in extreme temperatures because of their ability to maintain the internal body temperature, poikilotherms, heterotherms or cold-blooded animals are not found in extreme conditions because of an inability in adjusting their internal body temperature. Fishes, amphibians, reptiles, and invertebrates fall under the category of poikilotherms while birds and mammals fall under the category of homeotherms.
Different mechanisms support the survival of the cold-blooded and the warm-blooded animals. Some cold-blooded animals may release heat shock proteins or may undergo hibernation or aestivation to protect themselves from extreme conditions while warm-blooded animals may exhibit perspiration, panting, hibernation to regulate their body temperature.