Biology and biomedicine · Fair entry · August 2026 Demonstration
Thermal tolerance in intertidal snails
Intertidal gastropods experience a steep thermal gradient across a few vertical meters of shore, and their upper thermal limits are known to shift with acclimation history. This study asked whether exposure logged directly in the field predicts thermal tolerance measured in the laboratory, using 240 animals collected across three shore bands on four dates, with continuous temperature logging at each band for the six weeks preceding collection. Survival at thirty two degrees fell from eighty eight percent at the high shore to forty one percent at the low shore, and logged exposure above twenty five degrees predicted the temperature of reattachment failure more strongly than shore height alone. Within band variation was large enough that height predicts a population mean well and an individual animal poorly. The design is correlational and cannot separate acclimation from selection, which a transplant experiment would.