Table 5 Results from three-way ANOVAs with water exchange rates (high or low), rearing unit form (tank or raceway) and stress (baseline or exposed to an acute stress test) as grouping factors. Plasma cortisol or brainstem serotonergic activity (the ratio between serotonin [5-HT] and its immediate catabolite 5-Hydroxyindoleacetic acid [5-HIAA]) were continues variables

Water exchange rate

F_{(1, 36)} = 5.5, P < 0.05

F_{(1, 34)} = 0.4, P < 0.6

Raring unit form

F_{(1, 36)} = 14, P < 0.001

F_{(1, 34)} = 7.6, P < 0.01

Stress

F_{(1, 36)} = 190, P < 0.001

F_{(1, 34)} = 2.4, P < 0.13

Water exchange rate x rearing unit form

F_{(1, 36)} = 0.2, P < 0.6

F_{(1, 34)} = 0.15, P < 0.7

Water exchange rate x stress

F_{(1, 36)} = 11, P < 0.005

F_{(1, 34)} = 0.02, P < 0.9

Raring unit form x stress

F_{(1, 36)} = 25, P < 0.001

F_{(1, 34)} = 0.98, P < 0.33

Water exchange rate x Rearing unit form x Stress

F_{(1, 36)} = 0.02, P < 0.85

F_{(1, 34)} = 0.34, P < 0.6