Fig. 4From: Synergistic impacts by an invasive amphipod and an invasive fish explain native gammarid extinctionPrey selectivity of N. melanostomus. Mean values ± SE of electivity index are presented. Positive values represent preferred prey species in presence (open circles and squares) or absence (black circles and squares) of substratum. Dashed line indicates no selectivity. a Same size class of G. pulex and D. villosus. b Larger size class of D. villosus. Asterisks indicate significant differences to zero at p < 0.05 (repeated measures ANOVA): (*), p < 0.01 (**), p < 0.001 (***)Back to article page