Therefore, the great white shark can be considered an endothermic poikilotherm because its body temperature is not constant but is internally regulated.
It is this distinction that often makes the term poikilotherm more useful than the vernacular cold-blooded, which is sometimes used to refer to ectotherms more generally.
The lower proline and hydroxproline contents of cold-water fish and other poikilotherm animals leads to their collagen having a lower thermal stability than mammalian collagen.
Their poikilotherm metabolism has very low energy requirements, allowing large reptiles like crocodiles and the large constrictors to live from a single large meal for months, digesting it slowly.