(1) Ecology, Department of Human Sciences, University of Technology, LE11 3TU Loughborough, Leics., England;(2) Present address: Botany Department, University of Zimbabwe, P.O. Box 167, Mount Pleasant, Salisbury, Zimbabwe
Abstract:
The effect of low pH values on Daphnia magna is shown to severely depress the O2 uptake rates. The reason for this is discussed with respect to a decrease in the ability of the gills to exchange CO2 with the surrounding medium due to a reduction in the CO2 diffusion gradient as a result of increasing acidity. Respiration in CO2 free water at acid pH values is shown to be apparently unaffected.