摘要

The present study describes and validates a novel yet simple system for simultaneous in vivo measurements of rates of aquatic CO2 production (M. CO2) and oxygen consumption (M. O-2), thus allowing the calculation of respiratory exchange ratios (RER). Diffusion of CO2 from the aquatic phase into a gas phase, across a hollow fibre membrane, enabled aquatic M. CO2 measurements with a high-precision infrared gas CO2 analyser. M. O-2 was measured with a PO2 optode using a stop-flow approach. Injections of known amounts of CO2 into the apparatus yielded accurate and highly reproducible measurements of CO2 content (R-2=0.997, P<0.001). The viability of in vivo measurements was demonstrated on aquatic dragonfly nymphs (Aeshnidae; wet mass 2.17 mg-1.46 g, n= 15) and the apparatus produced precise M. CO2 (R-2= 0.967, P< 0.001) and M. O-2 (R-2= 0.957, P< 0.001) measurements; average RER was 0.73 +/- 0.06. The described system is scalable, offering great potential for the study of a wide range of aquatic species, including fish.

  • 出版日期2017-3-15