Ectotherm has an ability to get the animal 's body heat from the external

environment. Poikilotherms is different from ectotherm, but allows internal

temperature varied alot depending on its environment. Ectotherm and

poikilotherm are somewhat related having to do with an animal gaining its body

heat from an external source. Ectotherms and poikilotherm have fishes, reptiles,

and amphibians in there vertebrate group. Endotherm is an animal that maintains

its own internal metabolism by generating its own body heat. And homeotherm is

an animal that maintains a constant internal body temperature. Both of these

terms relate having to do with an animal gaining its body heat from an external

source. Endotherm and homeotherm have mammals