Meeting Abstract
Climate change is expected to contract the habitat range of the upper-mid intertidal porcelain crab, Petrolisthes cinctipes, increasing its population density and elevating behavioral stresses leading to decreased physiological performance. We aim to determine how increased density and competition impacts fecundity, a proxy for reproductive fitness, indexed by circulating levels of the yolk protein vitellogenin. Vitellogenin levels are closely tied to gamete quality and reduced concentrations of it under high-density conditions may result in smaller brood sizes and lower hatching success under future conditions, thereby reducing fitness. Female crabs were exposed either to high- (450 crabs/m2) or low-density (150 crabs/m2) treatments for 14 days. Hepatopancreas, ovary and hemolymph samples were harvested from each crab and analyzed using an ELISA assay to determine vitellogenin concentrations. Results were compared with heat shock proteins expression of individuals to assess degree of cellular stress response associated with cross treatments. We expected vitellogenin concentrations to be higher in low-density (low stress) treatments relative to high-density (high stress) treatments, and for heat shock proteins to have the opposite response. Understanding behavioral responses can will reveal the indirect physiological consequences through shifts in species interactions and population density.
