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. (fishionary.fisheries.org/eurytherm)

Desert Pupfish are eurythermic, surviving in temperatures ranging from function in waters from 4º to 45ºC (Paul V. Loiselle).