Modeling the Lethal Effects of High Temperature on Fish

We developed a mathematical model relating mean survival times of samples of fish at lethally high temperatures. It permits the estimation of upper incipient lethal temperature (UILT, degrees Celsius) from the results of short-term experiments. Application of the model to data sets obtained from the literature yields "predicted" UILTs usually within 0.5° and almost always within 1° of observed values. The model was also applied to determine threshold toxicities (LC50, 144 h) of copper ion from tests of shorter duration.