HENRY, M.: Modeling Body Temperature of Intertidal Snails: Hot Mud and Hot Bodies

Intertidal snails face a cyclical ambient environmental regime due in part to the tides. However, do their body temperatures change along with the ambient environment or do they act as biological filters, not being affected by factors like the drastic temperature change around them? In a preliminary study conducted in the Pacific Northwest, environmental parameters of solar radiation, ground temperature, air temperature, relative humidity, and wind speed, were examined to determine their effects on the body temperature of snail models (empty shells filled with modeling clay). Data on the environmental parameters were collected during two days, at approximately the same time of the tidal cycle, and used as tests of a mathematical model of heat flux. the thermal energy model included only conductoin, convection, IR radiation, and short-wave solar radiation terms. The mathematical model estimated body temperatures within 1.5 degrees of actual body temperatures recorded in teh field. Estimated body temperatures were within 0.5 degree of the ground temperatures, suggesting that the conduction term plays a large role in determining internal temperature of snails in rocky intertidal habitats. The ability to predict and explain the internal body temperature of intertidal organisms can be an aid in explaining population distribution, migration patterns, and operating temperature ranges.