Figure 2.

(a) Phototactic behaviour of uninfected and non-injected G. pulex (C) and those injected with 1 μl Ringer solution (R), octopamine (5 μg μl⁻¹) (O) or 5-HT (5 μg μl⁻¹) (S). (b) Geotactic behaviour of non-injected G. pulex (C) and those injected with 1 μl Ringer solution (R) or 5-HT (5 μg μl⁻¹) (S). Figures show median phototactism/geotactism scores, associated interquartile range, sample size and significance as determined by Kruskal–Wallis one-way test and 2×2 significance as determined by post hoc tests, ^***p≤0.0001.