Abstract: In order to understand the effects of water temperature on the aerobic locomotor capacity and its relationships with the energetic metabolism of juvenile Parabramis pekinensis the juveniles were put into the waters at different temperature (10, 18, 26, and 34 ℃) to measure their resting metabolic rate (RMR), critical swimming speed (U_crit), and maximal metabolic rate (MMR) during swimming, and the differences of MMR-RMR at different water temperature were used to calculate the metabolic scope (MS) of the juveniles. Both the U_crit and the RMR increased significantly with increasing water temperature (P<0.05). The U_crit was increased from 6.01±0.32 BL·s^-1 to 8.82 ±0.27 BL·s^-1 when the water temperature increased from 10 to 34 ℃, and the MMR increased significantly when the temperature increased from 10 and 26 ℃, and remained unchanged with the further increase of temperature. The RMR and MMR were 1617 ±28.81 mg O₂·kg^-1·h^-1 and 292.95 ±27.59 mg O₂·kg^-1·h^-1 at 10 ℃, and 558.55±20.41 mg O₂·kg^-1·h^-1 and 1278.74 ± 57.40 mg O₂·kg^-1·h^-1 at 34 ℃, respectively. The MS increased significantly when the temperature increased from 10 to 26 ℃ (P<005), but decreased significantly when the temperature further increased from 26 to 34 ℃. It was suggested that the different reaction patterns of the MS and U_crit to the changes of water temperature were possibly due to the high swimming efficiency as the results of the decreased water viscosity coefficient and the high anaerobic metabolism capacity of the fish at high water temperature.

Key words: upland red soil, biochar, microbial biomass, nematode assemblage.