The effects of four different levels of wood betony (WB) (Stachys lavandulifolia Vahl) extract (0, 2, 4 and 8% W/W in the diet) were investigated on some serum enzymatic activities and acute stress response of juvenile common carp (Cyprinus carpio). After 10 weeks post feeding, two groups of fish (0 and 8% WB) were subjected to handling and crowding stress and the stress responses including ser...