hosurus-a brush-tail possum, Sylvilagus-an eastern cottontail rabbit, Felis- a domestic cat, and Homo sapiens- a human. Student’s t-tests were performed, comparing metabolic rates for: each of the species tested at 5 C and 35 C, monotreme mammals and marsupial mammals, monotreme mammals and placental animals, and marsupial mammals and placental mammals. We also studied the relationship between metabolic rate and body size using crab oxygen consumption rates. A 5g and a 25g crab were used, and metabolic rates were measured at 23.5 C and 8.5 C. Student’s t-tests were used to compare the metabolic rates for: each crab at both temperatures, the small crab at 8.5 C with the large crab, and the small crab at 23.5 C with the large crab. ResultsComputer Simulations of Metabolic rates-We found the average oxygen consumption rate (in g/cm2 x 1000/hr) for the two montremes: Ornithorhyncus was 1.414 at 5 C and 0.759 at 35 C and Echidna was 1.515 at 5 C and 0.889 at 35 C. For the marsupials, the average oxygen consumption rate (in g/cm2 x 1000/hr) for: Bettongia was 1.160 at 5 C and 0.507 at 35 C, Dasyurus was 1.173 at 5 C and 0.688 at 35 C, Trichosurus was 0.818 at 5 C and 0.305 at 35 C. In the placental mammals, the average oxygen consumption rate (in g/cm2 x 1000/hr) for: Sylvilagus was 1.746 at 5 C and 0.983 at 35 C, Felis was 1.874 at 5 C and 1.188 at 35 C, and Homo sapiens was 1.629 at 5 C and 1.718 at 35 C. Figure 1 shows the effects of temperature on oxygen consumption rate for monotremes (Ornithorhyncus and Echidna), marsupials (Bettongia, Dasyurus, and Trichosurus), and placental mammals (Sylvilagus, Felis, and Homo sapiens). Figure 1. The effects of warm and cold temperatures on oxygen consumption rate for montremes, marsupials, and placental mammals.For each of the species, we compared the average metabolic rates at 5 C and 35 C. We found that at the two different temperatures, all of the species were statistically...
