(a) The larval fish do not show an obvious developmental defect when treated by ACh-Cl and LH+ACh-Cl for 12 hours compared with control. Left panels are in the BF channel, whereas right are in the GFP channel. (b–c) Quantification data indicate that the effect of exogenous ACh-Cl on gut peristalsis at 4 dpf (b) and 6 dpf (c) after transit incubation for 10–30 minutes. 10, 100, 1000, 2500 and 5000 mg/L ACh-Cl had no influence on the gut movement frequency at 4 dpf (b), whereas 2500 mg/L promote the movement ability obviously at 6 dpf (c). (d) Quantification data show that treatment of exogenous ACh-Cl for 10–30 minutes partially rescue the inhibition phenotype of gut peristalsis caused by LH. (e) Quantification data show that acetylcholinesterase (AChE) inhibits the recovered phenotype by exogenous ACh-Cl. P value is statistical with corresponding control.