Box-plot of body shape in function of groups. Body shape is defined by axis of the linear discriminant analysis on treatment effect. Considered groups are: Cnn = Chondrostoma nasus nasus; Ctt = Chondrostoma toxostoma toxostoma; Hy = Hybrids; HR = Highly regulated river part; LR = Less regulated river part. Deformation grid: orange: allopatric mean specimen; black sympatric mean specimen. The shape differences have been exaggerated three-fold for better visualization. Arrows indicate the main deformations (tendency to a spindle-shaped body and the snout steered upward in the hybrid zone).