MILLER, L. P.; Hopkins Marine Station of Stanford University: The effects of high temperature and desiccation stress on the survival of the giant owl limpet, Lottia gigantea

Temperature and desiccation are often invoked as limiting factors in the small-scale distributions of many rocky intertidal organisms. Many of the limpet species from the California intertidal zone have been characterized with regards to their lethal temperatures, but the giant owl limpet Lottia gigantea has been noticeably absent from previous studies. In the mid-intertidal zone Lottia gigantea can play an active role in determining the distributions of its neighbors; therefore, factors which affect the distribution of Lottia gigantea can have cascading effects through the community. Results of laboratory-based experiments involving high temperature and desiccation stresses on the survival of Lottia gigantea will be discussed. Preliminary results place the lethal temperature of Lottia gigantea near 38°C at 100% relative humidity. Lower humidity, as found under field conditions, leads to a depressed lethal temperature limit. Lethal temperature and desiccation limits will be compared to model predictions of temperatures reached by limpets in the field.