ACCLIMATION OF OXYGEN CONSUMPTION TO TEMPERATURE IN THE AMERICAN COCKROACH (PERIPLANETA AMERICANA)

¹ Department of Zoology, University of California, Los Angeles, 24, California

1. Oxygen consumption has been studied in cultures of nymphal and adult cockroaches, Peniplaneta americana, that have been maintained at two experimental temperatures (10° and 16° C.) and the control temperature (26° C.) for a period of one to three weeks.

2. It has been shown that the oxygen consumption of equal-weight nymphs when measured at 20° C. is higher in animals that have been maintained at the lower temperatures.

3. Comparison of cold- (10° C.) and warm-adapted (26° C.) nymphs when measured at a series of temperatures (10° to 25° C.) demonstrates that cold-acclimated animals consume more oxygen per gram per hour than equal weight warm-adapted ones.

4. Adult cockroaches show acclimation of their oxygen consumption to temperature. However, there isa differential response with respect to size; small adults acclimate to a greater degree than large ones. Further, all sizes of nymphs show a greater degree of acclimation than all sizes of adults.