Size of Madagascar Hissing Cockroaches at Lower Ambient Temperatures: Effect on Cellular Respiration

Abstract

Madagascar Hissing Cockroaches (Gromphadorhina portentosa) are ectotherms useful in the study of cellular respiration and thermoregulation. Variations that can be found in respiration and metabolic rates include body size, behaviors, color, and wind speed (French 2017). This raises the question; does the size of the MHC determine the cellular respiration at lower ambient temperatures? To test this hypothesis, two large Madagascar Hissing Cockroaches (MHC) and two small MHC were monitored in small respiration chambers for a duration of 4 minutes while measuring carbon dioxide (CO2) production with a CO2 probe and monitoring the temperature of the chamber with a temperature probe. An experiment was run for both sample sizes at room temperature and then a colder ambient temperature to measure the different levels of CO2, allowing the MHC to rest between experiments. It was found that respiration was significantly different between the larger and smaller MHC at lower ambient temperature. Results found that the smaller MHC produced significantly more CO2 at the lower ambient temperature than their larger counterparts.