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Ectotherms |
Endotherms Greek: "endo" (inside) & "therm" (heat) |
Commonly referred to as cold-blooded Cannot generate their own body heat; depends on external environment to regulate body temperature Most of their body heat obtained from external sources, such as the sun; Warms the body by absorbing heat from their surrounding environment (basking in the sun) Take on temperature of surroundings; when in hot temperatures, they are hot; when they are in cold temperature environments, they are cold. Body temperature fluctuates (changes) when surrounding temperatures change; poikilotherms experience fluctuating body temperatures More active in warm environments; Less active in cold environments Muscle activity depends on chemical reactions that run quickly when it is hot, slowly when it is cold Can convert much more of their food into body mass than endotherms Eat less food than endotherms Need less food when it is cold because activity level slows |
Commonly referred to as Warm-blooded Can generate body heat internally by converting food they eat into energy (process of metabolism) Most of their body heat obtained from internal sources Body temperature is relatively constant; maintains stable body temperature even though they are in cold or hot surroundings; homeotherms experience nearly constant body temperature levels Can be active in cold and warm environments; muscle activity does not depend on warm temperatures in surroundings Needs to consume enough food to maintain stable internal body temperature; needs food to fuel the internal body temperature controls Needs more food than ectoderm; most of the food that is eaten is turned into fuel to maintain constant body temperature Most of their body heat is generated internally through metabolism |