Larger Group Size Negatively Affects Respiration Rates of Madagascar Hissing Cockroaches

Abstract

Ectotherms are organisms that cannot regulate their own metabolic temperature. Experiments have been done in the past relating body size and heat retention, such as larger organisms taking a longer amount of time to lose heat. There were few studies done relating group size and respiration. Our experiment measures respiration of Madagascar Hissing Cockroaches at cold temperatures in varying group sizes. We hypothesized that the metabolic rate of the cockroaches would increase with increasing group size because the heat exchange between the cockroaches together would result in heightened respiration. We measured the oxygen consumption of the cockroaches in changing group sizes and a constant temperature in a large compartment chamber. Our experiment showed that larger groups respired less. Our hypothesis was not supported by our results, showing that as the group size increased the respiration actually decreased. Though there were some flaws in our experiment, we came to a conclusion that there could be an alternative hypothesis from our results and that there should be further research completed in order to reach a firmer conclusion.