The animals in the animal kingdom are grouped into two categories based on 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 warm-blooded or homeothermic. In contrast, those animals who cannot maintain their body temperature internally and change according to the temperature change in the surrounding environment are known as cold-blooded or poikilothermic animals.
Cold-Blooded vs Warm-Blooded
The main difference between Warm-blooded and cold-blooded animals is that the cold-blooded cannot maintain a constant internal body temperature as per the changing temperature of the surroundings. In contrast, warm-blooded animals can maintain their internal body temperature to a constant value even if the temperature of their 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 differentiates the fishes, amphibians, reptiles, and other invertebrates from birds and mammals. Since these animals depend on environmental conditions to maintain warmth inside their body, they thrive in limited temperature ranges.
Warm bloodedness, also known as homeothermy, is the organism’s ability 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 a 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 | Constant body temperature ranges between 35-40°C | High metabolic rates help to produce large amounts of energy and heat |
| Body Temperature | Body temperature changes according to a change in the temperature of their respective surroundings. | High metabolic rates help to produce large amount of energy and heat |
| 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 to maintain their body temperature, they are found in a very limited temperature range. Their terrestrial distribution is limited, with only a few exceptional cases in a 5-10°C temperature range and 35-40°C.
However, cold-blooded animals can 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 low compared to warm-blooded animals. However, even a slight fluctuation in their body temperature may dramatically change their internal body temperature.
Several adaptations help the cold-blooded animals to survive the changing weather conditions. As the temperature of the surroundings starts rising, 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 important proteins and protect them from overwhelming high temperatures.
What is Warm-Blooded?
Warm bloodedness, also known as homeothermy, is the organism’s ability 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 retain heat in cold surroundings, 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 cold climate. Perspiration and panting increase heat loss through the body and maintain the body temperature. Birds and mammals are homeothermic animals, so they are found in different temperature zones. Their ability to adapt to 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 cold-blooded animals’ internal body temperature changes according to 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 are 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 and stretching their hands and feet. In contrast, warm-blooded animals may regulate their body temperature by perspiration, panting, and 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 survival mechanisms, and each of these mechanisms is important. While homeotherms or warm-blooded animals are found in extreme temperatures because of their ability to maintain their internal body temperature, poikilotherms, heterotherms or cold-blooded animals are not found in extreme conditions because of an inability to adjust 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 undergo hibernation or aestivation to protect themselves from extreme conditions. In contrast, warm-blooded animals may exhibit perspiration, panting, and hibernation to regulate their body temperature.
