Respiration Studies on the Antarctic Collembolan Cryptopygus antarcticus

Analyses are presented of 190 measurements of individual respiration rate for the complete size range of Cryptopygus antarcticus Willem. A Cartesian Diver micro-respirometer was used at Signy Island (Maritime Antarctic) during the austral summer 1971/72. Oxygen consumption per individual increased linearly with live weight on a log basis at 0°, 5° and 10°C. The 5° and 10°C regression lines differed significantly and the weight exponent b varied from 0.669 to 0.825. Mean oxygen uptake rates for 5 size classes ranged from 0.671 to 22.610 μ 1× 10-3 O2 ind-1 h-1, and from 95.66 to 469.20 μ 1 O2 g-1 h-1 over the temperature range studied. Juveniles showed least change in rate, and adults the maximum change, over 0° to 10°C. Egg respiration was 0.306 μ 1× 10-3 O2 h-1 at 5°C. Data are compared with other Antarctic Collembola, and temperate species. Comparison of respiration rates with cultured, acclimated animals showed considerable differences. Cultured juveniles have much higher rates, especially above 5°C, than field animals. Population metabolism is estimated for a typical habitat and cold adaptation is discusse