S. lucioperca predator–prey relationships in the Grand Union Canal. (a) Predator size to prey size linear relationships (with 95% confidence intervals) for ‘Cyprinidae’ (● solid line) and ‘Percidae’ (▲ dashed line). (b) Prey: predator length ratios versus S. lucioperca body length, where lines represent relationships according to linear regression for ‘Cyprinidae’ (● solid line) and ‘Percidae’ (▲ dashed line). (c) Relative frequency distributions of prey: predator length ratios, where the mean prey size to predator size ratio is shown at 0.22.