Ectotherm
Unlike endotherms which can metabolically control their own body temperature, ectotherms rely upon environmental temperatures for thermoregulation. Most fish are ectotherms. Ectothermy can be metabolically more efficient than endothermy because organisms do not have to expend any energy to self-regulate their body temperatures. However, they are at the mercy of their environment more than endotherms because they … [Read more…]