Heavy Breathing: How Mass Affects the Respiration Rate of Milkweed Bugs

Abstract

Aerobic respiration rate is the speed at which the cells of an organism convert oxygen into energy and release waste in the form of carbon dioxide. We tested ectothermic milkweed bugs (Oncopeltus fasciatus) of different body masses to see if there is a correlation between body mass and aerobic respiration rate. We recorded the masses of two groups of milkweed bugs that varied in mass, and measured the amount of carbon dioxide output to determine the rate of respiration. Our experiment yielded a negative correlation between the body mass and aerobic respiration of ectothermic milkweed bugs. This experiment did not support our hypothesis that an ectotherm with a higher mass produced a higher amount of carbon dioxide.