Eurytherm
In contrast to stenotherms, eurythermic fish can function at a wide range of water temperatures. They are often, but not necessarily, ectotherms. Desert Pupfish (Cyprinodon macularius), for example, can function in ambient temperatures ranging from 4 to 45 degrees Celsius. This thermoregulatory strategy requires that organs, enzymes, and metabolic processes can operate at varying environmental temperatures.