Increasing measurement temperatures corresponded with increasing P50 values for both 20 °C- and 24 °C-acclimated yellowfin between 20 and 35 °C, and for 17 °C-acclimated yellowfin between 25 and 35 °C. Individual P50 value comparisonswere significantly different for 17 °C-acclimation between 25 °C and both 20° and 35 °C, for 20 °C-acclimation between 35 °C and both 20° and 25 °C, and for 24 °C-acclimation between 35 °C and all other measurement temperatures.