Meeting Abstract
Many of the consequences of global change are expected to result from changes in species interactions. Therefore, it is critical to understand the mechanisms by which thermal stress is transduced through behavioral interactions. The porcelain crab Petrolisthes cinctipes resides in the upper to mid intertidal zone and is expected to behaviorally respond to rising temperatures by shifting its distribution to a lower position in the intertidal zone. If they move down the shore, they will experience higher densities and likely interact more often with a congeneric competitor, Petrolisthes manimaculis. In this study, we addressed how increased density and inter- and intra- species interaction impacts survival and reproduction, indexed by circulating levels of the yolk protein vitellogenin (Vg). To address these questions, female crabs were randomly exposed to high density (787 crabs/m2) or low-density (200 crabs/m2) treatments with and without the presence of a competitor species for 14 days. We found that density and interspecific interactions both influenced survival in a species-specific manner, as P. manimaculis experienced significantly more mortality in high-density and interspecific treatments than P. cinctipes. Additionally, ELISA results show elevated Vg concentrations in P. manimaculis relative to P. cinctipes suggesting possible reabsorption of the protein in response to stressful behavioral interactions. Our results highlight the importance of species interactions under changing conditions and further our understanding of how thermal stress can impact animal populations through increased behavioral stress.
