Fig. 2. The effects of cortisol and cortisol+RU486 treatments on plasma cortisol concentrations in (A) size-matched (respectively, 14 and 10 pairs) and (B) size-mismatched (respectively, 11 and 10 pairs) rainbow trout Oncorhynchus mykiss confined in pairs for 5 days. Values are means ± 1 S.E.M.; N values are given in the figure. Means were calculated for each combination of social status and treatment within a treatment group to give dominant treated, subordinate treated, dominant untreated, and subordinate untreated categories. See text for statistical analysis of these data.