Effects of temperature, salinity, and pH on the survival and activity of marine cercariae.

Alterations of abiotic factors due to global climate change are predicted to impact disease dynamics, particularly for pathogens with complex life cycles involving free-living infectious stages, such as the cercariae of trematode parasites. Previous investigations of cercarial output, longevity, and infectivity suggest an overall increase in trematode transmission in response to elevated temperature. However, while increased temperature will likely be accompanied by changes in salinity and pH in marine ecosystems, little is known regarding their influence on cercariae.