26 8.1 Cold-blooded and warm-blooded organisms
1Body temperature
Cold-blooded (poikilotherms / ectotherms)
- changes with the surroundings
Warm-blooded (homeotherms / endotherms)
- kept constant by metabolism
2Heat source
Cold-blooded (poikilotherms / ectotherms)
- external: sunlight, warm environment
Warm-blooded (homeotherms / endotherms)
- internal: metabolic processes
3Groups
Cold-blooded (poikilotherms / ectotherms)
- most vertebrates: fish, amphibians, reptiles; all invertebrates such as arthropods, molluscs
Warm-blooded (homeotherms / endotherms)
- birds and mammals
4Energy need
Cold-blooded (poikilotherms / ectotherms)
- low (they need less food)
Warm-blooded (homeotherms / endotherms)
- high (much of the food energy is used to make heat)
5Dependence on stable water temperature
Cold-blooded (poikilotherms / ectotherms)
- high
Warm-blooded (homeotherms / endotherms)
- lower