Cockroaches that exchange respiratory gases discontinuously survive food and water restriction

Metabolic rate and respiratory gas exchange patterns vary significantly both between and within species, even after a number of biotic and abiotic factors are taken into account. This suggests that such variation is of evolutionary importance, but the life history implications of this variation remain relatively poorly characterised. In the present study we examine the effect of metabolic variation on starvation and desiccation resistance in the speckled cockroach Nauphoeta cinerea. We also compare the starvation and desiccation resistance of individuals that exchange respiratory gases continuously with those that breathe discontinuously. We show that metabolic rate has no effect on survival during food and water restriction, but cockroaches exhibiting discontinuous gas exchange cycles (DGCs) live longer than those that do not and those provisioned with water lived longer than those that were not. This finding represents the first demonstration that DGCs confer a fitness benefit, and su...