Mortality of the New Zealand mudsnail, Potamopyrgus antipodarum, collected during the winter and spring at five salinities. Mortality values (mean percentage ± SE) are given at the end of 5 and 50 days for the winter and spring experiments, respectively. Grey and black bars show water temperature (5 and 10 °C) of Capitol Lake at the time of capture and thermal shock treatments (20 °C), respectively. Different letters indicate significant difference in mortality between salinity treatments within each experimental temperature (p < 0.05 ANOVA, Tukey post hoc comparisons).