TEMPERATURE EFFECTS ON LOCOMOTOR-ACTIVITY RATES OF SUB-ANTARCTIC ORIBATID MITES

The influence of temperature on locomotor activity was determined for the sub-Antarctic mites, Halozetes fulvus Engelbrecht and Podacarus au berti Grandjean. In both species walking was severely impaired at belo w-freezing temperatures. Above zero, locomotor activity rates increase d with a rise in temperature over a wide temperature range (for exampl e, this was 2-30-degrees-C for H. fulvus), and they showed a biologica lly normal level of sensitivity to change in temperature. All the calc ulated Q10 values for mean rates over 5-degrees intervals varied betwe en 1.3 and 2.9. The present data are compared with some rate functions of maritime and continental Antarctic micro-arthropods, and they conf irm the relative enhancement of the physiological rate by a continenta l Antarctic mite. One explanation for the less temperature-sensitive r ates in H. fulvus and P. auberti may be that they have relatively more time available for normal biological activity.