An ectothermic animal, also commonly known as a "cold-blooded" animal, is one who cannot regulate its own body temperature, so its body temperature fluctuates according to its surroundings. The term ectotherm comes from the Greek ektos, meaning outside, and thermos, which means heat.

What does ectothermic mean for animals?

ectotherm, any so-called cold-blooded animal—that is, any animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface. The ectotherms include the fishes, amphibians, reptiles, and invertebrates.

What does ectothermic and endothermic mean?

An ectotherm (reptile/amphibian) relies primarily on its external environment to regulate the temperature of its body. Endotherms (birds) are able to regulate their body temperatures by producing heat within the body.