Relative expression of TrCLCN5 mRNA in Takifugu rubripes gills under low-salinity stress at different time points. After normalization to β-actin, relative expressions of TrCLCN5 mRNA were calculated using the 2-ΔΔCt method. Bars represent the mean ± SD. The * indicates significant differences from the control group (p < 0.05).