Fig 1. Schematic diagram explaining the experimental design of the present study.

Abbreviations:—CS, fish group that was not challenged by cold stress; + CS, fish group that was challenged by cold stress;—PR, fish group that received a basal diet with no propolis supplementation; + PR, fish group that received a basal diet with 10 g/kg propolis; FBW, final body weight; BWG, body weight gain; SGR, specific growth rate; FI, feed intake; FCR, feed conversion ratio; CMR, cumulative mortality rate; GSH, reduced glutathione; SOD, superoxide dismutase; CAT, catalase; MPO, myeloperoxidase; MDA, malondialdehyde; TWBC, total white blood cells; H/L ratio, heterophil to lymphocyte cell ratio; PBL-SI, peripheral blood leukocyte stimulation index; PA, phagocytic activity; LA, lysozyme activity.