Hemigrapsus nudus Feeding on Ulva lactuca When Exposed to High Salinity and High Temperature

Abstract

Hemigrapsus nudus is a species of crab that dominates the intertidal of the Pacific Coast in North America, making them valuable to the intertidal ecosystem through their large contribution to the food web. H. nudus is exposed to a wide range of salinities and temperatures within the intertidal. To determine if elevated salinities and temperatures affect H. nudus I conducted a study to monitor the crabs feeding on Ulva lactuca when exposed to different conditions: high salinity, high temperature, and ambient control. I hypothesized that high salinity and high temperature will have an impact on H. nudus feeding. The crabs exposed to high salinity showed the greatest variance in consumption rate. However, an R generated ANOVA showed no difference in the feeding rate of H. nudus when exposed to the different treatments. Overall, H. nudus showed no detectable response to slight elevations in temperature and salinity.