Fig. 1

Experimental design and respiratory metabolism detection system. A The experiment consisted of two treatments: 4 °C and 17 °C, where G. przewalskii was maintained for 15 days. For each treatment, 20 specimens were maintained in three independent replicate tanks (1, 2, and 3). On sampling day (day 15), three fish per replicate tank (n = 3) were randomly sampled for RNAseq, two fish per replicate tank (n = 2) were randomly sampled for LC–MS/MS, and two fish per replicate tank (n = 2) were randomly sampled for histology. B A schematic plot of the respiratory metabolism detection system. In each test group (4 °C and 17 °C), six fish were selected randomly for routine metabolism rate (RMR) detection. Individual fish was placed in a 250 mL chamber, submerged in a 100 L outer tank supplied with fresh water at 4 °C or 17 °C. Each chamber was connected with an internal recirculation water pump (WP) and a flush WP. Chamber oxygen partial pressure (pO2) was measured with an OXY-4mini (PreSens, Regensburg, Germany) fiber optic O2 transmitter, connected to a computer. A temperature control system was connected to the outer tank and the water temperature controlled at a desired value