Comparison of oxygen consumption in drosophilid flies from different climates

Abstract

AbstractOxygen consumption at rest was studied in drosophilid species from cool‐temperate, warm‐temperate and subtropical regions to assess whether adaptations to different climates are associated with changes in metabolic rates. In experiments at 23°C using 8‐day‐old males of 28 species, body mass was revealed to be a significant predictor of oxygen consumption. No significant relation was detected between mass‐adjusted oxygen consumption and latitudinal distribution or thermal tolerance by either conventional regression analysis or a phylogenetically based method. The effect of temperature on oxygen consumption was studied with experiments at 15, 18, 23 and 28°C using 8‐ and 24‐day‐old males of four species of each of the montium species subgroup and the subgenus Drosophila. In these experiments, it was confirmed that temperature was a significant predictor of mass‐adjusted oxygen consumption. In both lineages, mass‐adjusted oxygen consumption was not higher in cool‐temperate species than in subtropical species. Thus, adaptations to colder climates are not associated with elevation of metabolic rates in these drosophilid species. The results of the present study also indicate that oxygen consumption is not related to the capacity to walk quickly.