Are Fish Endothermic

Though rare, some fish are able to internally regulate temperature. Unlike ectotherms, which rely upon environmental temperatures, endotherms are able to metabolically control their body temperature. Tunas are one example of endothermic fish. …

Are all fish endotherms or ectotherms?

Unlike endotherms which can metabolically control their own body temperature, ectotherms rely upon environmental temperatures for thermoregulation. Most fish are ectotherms.

Why are fish not endothermic?

Many fishes, such as tuna, actually have a physiological mechanism that enables them to be at least partially endothermic. They use a counter-current circulatory system called the rete mirabile (Latin for “wonderful net”), which exchanges venous blood (going to the heart) and arterial blood (going from the heart).