Physiological Ecology of "Herbivorous" Antarctic Copepods

Polar marine organisms have adapted to dramatic seasonal changes in photoperiod, light intensity, and ice cover, as well as to cold but stable thermal environments. The western Antarctic Peninsula, the focal region for the field studies, has experienced rapid warming and ice melt. While it is difficult to predict exactly how physical conditions in this region will change, effects on species distributions have already been documented. Large Antarctic copepods in the families Calanidae and Rhincalanidae are dominant components of the mesozooplankton that use different metabolic and behavioral strategies to optimize their use of a highly seasonal food supply. The overall goal of this project is to leverage molecular approaches to examine the physiological and metabolic adaptations at the individual and species level. The project focuses on three main objectives: the first objective is to characterize the gene complement and stage-specific gene expression patterns in Antarctic copepods within an evolutionary context. The second objective is to measure and compare the physiological and molecular responses of juvenile copepods to variable feeding conditions. The third objective is to characterize metabolic variation within natural copepod populations. The metabolically diverse Antarctic copepods also provide an excellent opportunity to compare mechanisms regulating energy storage and utilization and to test hypotheses regarding the roles of specific genes. The field studies will aim to utilize information from an ongoing long term research program (the Palmer Long-Term Ecological Research), which complements the ongoing program and provides extensive context for this project. To make the data more useful to the research community, a database will be developed facilitating comparison of transcriptomes between copepod species. This project will provide hands-on training opportunities to graduate and undergraduate students. Results and scientific concepts will be broadly disseminated through an expedition blog, undergraduate student programs, and public presentations.