How Body Size Affects Metabolic Rate in two cockroach species: Gromphadorhina portentosa or Blaptica dubia

Abstract

The metabolic rate of organisms is a very important topic for understanding how organisms’ function differently, specifically body size is often thought to be a contributing factor to metabolic rate. We want to test how body size influences the metabolic rate of two species of cockroaches (Gromphadorhina portentosa or Blaptica dubia). To determine the metabolic rate, we calculated the differences in the CO2 levels and mass for the different experimental groups to obtain an average metabolic rate for each species. To test our hypothesis, we had 4 trials of each group of cockroaches that was put into a respiration chamber where CO2 was released. We found that our hypothesis was not supported because the smaller cockroaches had a higher metabolic rate. By having a smaller surface area to volume ratio in this experiment, we could see that the metabolic rate would be more elevated than an organism that had a bigger surface to area volume.