Cold-blooded animals and warm-blooded animals are two groups of animals on the basis of regulating the internal body temperature. Cold-blooded animals are the group of animals that cannot regulate their internal body temperature according to the required level and keep changing their body temperature according to the changes in the external environment temperature. On the other hand, warm-blooded animals try to keep their internal body temperature maintained and do not let it change along with the changes in the external environment.
If it is cold in the external environment, the body of the warm-blooded animals tries to adapt according to the situation and generate heat which provides warmth to the body. Cold-blooded animals are unable to maintain this and instead, their body temperature is changed according to the external body temperature.
|Basis for Comparison||Cold-blooded Animals||Warm-blooded Animals|
|Definition||Cold-blooded animals are those animals that cannot maintain their internal body temperature according to the change in the external temperature.||Warm-blooded animals are those animals that can maintain their internal body temperature according to the change in the external temperature.|
|Energy usage||Needless energy to maintain body temperature||Need more energy to maintain body temperature|
|Phase||Hibernation (winter sleep) and aestivation (summer sleep)||No such phase|
|Temperature dependency||Dependent on the outer environment||Independent on the outer environment|
|Survival||Cannot survive in extreme environments||Adaptable to the extreme environments|
|Metabolic rate||Changes according to the environment||Changes with the environment|
|Body temperature||Changes with the environmental temperature||Does not change with the environmental temperature|
|Defense mechanism||Use body temperature||Immune system|
|Types||Three groups; Ectothermy, poikilothermy and brady metabolism||Three groups; Endothermy, homeothermy and tachymetabolism|
|Example||Reptiles, amphibians, fish and invertebrates etc||Fish and mammals|
What are Cold-blooded animals?
Cold-blooded animals are those animals which are not able to regulate internal body temperature. They depend on the sunlight to get themselves warm. When the external environment is cold their body tends to be cold and when the external environment is warm, their body tends to be warm.
Cold-blooded animals require less amount of food as their need for energy is very low for survival. They use their body temperature as their defense mechanism. They are more resistant to the disease as they do not allow harmful microorganisms and parasites to grow. If they catch any disease, they lower their body temperature to get rid of that disease.
Cold-blooded animals are very sluggish in the cold environment and wait for suitable temperature to get themselves warm. In a hot environment, these animals can have blood that is much warmer than warm-blooded animals and are very active. Fish moves to the deeper part of the water where the temperature of the water is warm as compared to the part they live. Some fish may die in the winter season. Bees produce heat with the help of the movements of the wings.
Cold-blooded animals have two phases of life; hibernation and aestivation. These are the resting period in winter and summer to maintain body temperature. Hibernation is the winter resting period in warm places for weeks or months whereas aestivation is the summer resting period in shady or cool places. They may mate and reproduce in the aestivation phase. Fish, reptiles, frogs, crocodiles, amphibians, bees, termites and moths are examples of cold-blooded animals.
Cold-blooded animals are of three types; ectothermy, poikilothermy and bradymetabolis.
- Ectothermy: The cold-blooded animals of this group maintained their body temperature according to the external environmental temperature. If there is sunlight, their body temperature will change accordingly and at night time, their body temperature will be cool. Reptiles are examples of ectothermy.
- Poikilothermy: The body temperature of these cold-blooded animals fluctuates with the variation in the temperature of the surrounding medium. Frogs and turtles are examples of the poikilothermic cold-blooded animals.
- Bradymetabolism: These cold-blooded animals maintain their body temperature according to the rate of metabolism. Insects show this behavior.
What are Warm-blooded animals?
Warm-blooded animals are those animals that can maintain their body temperature. Mitochondria of these animals produce energy that is utilized by the body to maintain body temperature. Body temperature remains constant in the range of 35° to 40° throughout life.
Warm-blooded animals use thermal homeostasis to maintain body temperature. If the outside environment is extreme, the body may change a little bit to maintain it or they release excessive heat by the process of sweating or painting. Whales do not need sweat glands as they live in water whereas elephants swear through the ear. At the time of extreme cold, fur, shivering and sometimes the migration of birds to the warmer region are used to maintain the body temperature.
Warm-blooded animals are very active in the cold as well as in a warm environment. They use the immune system to fight with the diseases as it is very strong in these animals. These animals have strong stamina as their body produces a lot of energy due to high metabolism rate.
Warm-blooded animals are of three types; endothermy, homeothermy and tachymetabolism.
- Endothermy: These warm-blooded animals maintain their body temperature by the use of internal means such as sweating, shivering etc. For example, a dog is the endothermy animal.
- Homeothermy: These animals’ body regulates their internal temperature irrespective of the external temperature. The body tends to maintain a higher temperature than the surrounding. Humans are an example of homeothermy.
- Tachymetabolism: These warm-blooded animals use a high metabolism rate to maintain body temperature. An example is birds.
Key Differences between Cold-blooded and Warm-blooded Animals
- The body temperature of fish, invertebrates, reptiles and amphibians fluctuates according to the changes in the external environment whereas warm-blooded animals maintain their body temperature according to the changes in the environment,
- Cold-blooded animals require less amount of energy whereas warm-blooded animals require a high amount of energy.
- The rate of metabolism of cold-blooded animals also changes with the change in the temperature of the external environment whereas the rate of metabolism of warm-blooded animals does not change with the change in the external environment.
- Cold-blooded animals have low metabolic activity whereas warm-blooded animals have high metabolic activity.
- The body temperature of the cold-blooded animal’s changes with the change in the external environment whereas the body temperature of the warm-blooded animals remains constant 35° to 40°.
- Cold-blooded animals undergo two phases of life; hibernation and aestivation whereas warm-blooded animals do not undergo such phases.
- Cold-blooded animals use their body temperature as a defense mechanism whereas warm-blooded animals have the immune system to defend themselves.
- Cold-blooded animals can convert much more of their food into the body mass compared with warm-blooded animals
In conclusion, cold-blooded animals and warm-blooded animals differ from each other on the basis of regulation of body temperature according to the surrounding.