Adaptation and stress defence in intertidal and subtidal Antarctic limpets (Nacella concinna):A study of the plasticity of molecular and biochemical stress response in Antarctic invertebrates

In the summer months, a subpopulation of the Antarctic limpet Nacella concinna migrates into the intertidal zone, which becomes increasingly ice-free and expands by glacier retreat due to global warming. Animals inhabiting intertidal zones are air exposed twice a day during low tide while sub-littoral animals are always covered by water. Intertidal and permanently sub-littoral N. concinna can easily be distinguished by their shell morphology. To test whether these morphological differences are accompanied by a physiological adaptation to the intertidal environment, I investigated the biochemical and molecular response of both limpet subpopulations to air exposure and hypoxia, a possible result of desiccation, if the limpets clamp down their shell to the substratum to avoid water loss. The results obtained within my thesis clearly indicate a physiological and molecular adaptation of the intertidal N. concinna to desiccation stress which the sub-littoral limpets do not show. These adaptations enable the limpets to survive in this extreme environment and will potentially allow the repopulation of emerging areas due to glacier retreat.