ABSTRACT
The oxygen-consumption rates of Asellus aquaticus (males and females) have been measured at 10 and 20° C. using a constant-volume respirometer, and the effect of starvation for 24 hr. investigated. The oxygen consumption is approximately proportional to the 0.7 power of the wet weight. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 1-5.
The oxygen-consumption rates of A. aquaticus and A. meridianus have been measured at 20° C. in a flowing-water respirometer employing a polarographic technique for the measurement of dissolved-oxygen concentrations. The oxygen consumptions of A. aquaticus and A. meridianus are similar and decrease by 15-20% when the dissolved-oxygen concentration falls from 8.3 to 1.5 p.p.m.
The oxygen consumption of A. aquaticus is between 35 and 75 % higher in the polarographic respirometer than in the constant-volume respirometer.
These experiments were carried out by Mr R. W. Edwards, whilst on the Staff of the Freshwater Biological Association.
For details of mercury level control and pre-treatment of capillary tubing see British Patent Application No. 40151/59.
Females with brood pouches were not used in these experiments.
The average of the respirometer influent and effluent concentrations has been taken throughout this paper. Generally the conditions, for example, flow and animal numbers, were arranged so th at a fall of about 1 p.p.m. could be expected.
