Abstract
This study aimed to determine salinity tolerances in Coxiella gastropods from Australian salt lakes and whether different species exhibit characteristically different tolerances. Controlled gradual accumulation experiments were conducted to estimate both the maximum and minimum salinity levels at which 50% of individuals (IC50) remained active for 25 populations representing six species. All studied species showed remarkable euryhalinity and were tolerant of very high levels of salinity, some more than others, while minimum salinity tolerance varied little among populations and species. The experimental trends in salinity tolerances were consistent with the salinity distributions of species in the field, although the former were typically broader than latter. The findings suggest that Coxiella comprises some of the most salt tolerant gastropods globally.