Effect of Hot and Cold Temperatures on Metabolic Rate in Madagascar Hissing Cockroaches (Gromphadorhina portentosa)

Abstract

Madagascar hissing cockroaches (Gromphadorhina portentosa) are ectotherms, which rely on their environment and behavioral mechanisms for thermoregulation. We decided to see if these cockroaches’ metabolic rates were to change if they were put in different temperatures. We hypothesized that if the cockroaches are subjected to higher ambient temperatures then the cockroaches’ metabolic rate will be higher due to the cockroaches being ectotherms. In order to test our hypothesis, a total of three cockroaches were introduced to three different ambient temperatures for 3 minutes, in which time CO2 rates were collected to later be used to calculate metabolic rate.  In this experiment we found that when the cockroaches were put in room temperature, which was our control, their rates slowly went up. However we surprisingly noted an increase in metabolic rate in the cold trials in comparison to the heated trials. These findings due not support our hypothesis as it indicates that the ectothermic cockroaches’ metabolic rate actually possessed a negative correlation with temperature.