Meeting Abstract
Increased temperatures from global warming can lead to lethal temperatures for the intertidal crab Petrolisthes cinctipes (Decapoda: Anomura). Physiological stress from increased temperature may force redistribution into cooler environments (Stillman and Somero 1996). As a result, interspecific interactions and increased population density may occur that threaten the fitness of its congener, P. manimaculus, through behavioral encounters. To investigate the effects of interspecific interactions, increased population density, and thermal stress, P. cinctipes and P. manimaculus were collected from November 2017 through July 2018 and exposed to thermal stress and placed at high and low densities with conspecifics and congeners. Hemolymph samples were taken from each crab before and after density and thermal stress treatments. To quantify the effects of treatments, an ELISA was used to quantify Vg levels in hemolymph before and after treatment (Delmanowski et al. 2017). During summer months, P. cinctipes showed decreased vitellogenesis, likely due to annual thermal stress (Salas 2017). Increased interspecific and intraspecific species interactions in high densities with thermal stress impaired vitellogenesis in P. manimaculus. At low densities vitellogenesis in P. manimaculus increased. These data suggest that the relocation of P. cinctipes into the lower intertidal can cause interspecific species interactions that are stressful for P. manimaculus at high densities. Thus, an increase in thermal stress to P. cinctipes that causes a migration into P. manimaculus habitat, can also cause a decline in the latter’s reproductive output.
