Fig. 4

Hepatic glycogen content (measured with the biochemical glycogen assay) of brown trout fry exposed to metformin at 7 °C and 11 °C; the number n of examined fish individuals is indicated (reduced number of samples due to pre-tests and exclusion of values out of calibration curve). The line within the boxes represents the median, the boxes are bordered by the 25% to 75% quartiles, the whiskers show the minimum and maximum values, the black dots are outliers. The asterisk indicates a significant difference compared with the respective control at the p = 0.05 level (nested ANOVA: 7 °C: p = 0.0620; 11 °C: p = 0.0085 (with Dunnett’s Test: (0 µg/L|1 µg/L): p = 0.0024))