Fig. 5

The Wnt activator Lithium chloride (LiCl) reduces the detrimental effects of stormwater treatment on the developing lateral line. All experiments were performed on Brn3c:mGFP fish treated from 4 hpf to 4 dpf. (a) Representative confocal images of the OP1 neuromast from zebrafish larvae raised in different stormwater concentrations, with and without the presence of LiCl. The scale bar in the upper left = 10 µm and applies to all panels. (b) Quantitative data showing significantly fewer hair cells in fish raised in stormwater from January 2016 (black bars), and prevention of hair cell loss when fish were raised in the same stormwater with LiCl present (gray bars). Similar to previous experiments, stormwater caused a significant decrease in hair cell number (two-way ANOVA, F_2,72 = 10.15, p = 0.0001). LiCl-treated fish had significantly more hair cells than fish reared without LiCl (two-way ANOVA, F_1,72 = 35.09, p < 0.0001). The interaction between the stormwater and LiCl treatments was also significant (two-way ANOVA, F_2,72 = 3.819, p = 0.026). Asterisks indicate significant pairwise differences between -LiCl and + LiCl groups for a given stormwater concentration (****p < 0.0001). N = 10–16 fish per group treatment, bars are + 1 s.d.