The effects of arecoline on locomotor activity. The effects of different concentrations of arecoline on the development (A, B) and locomotor activity (C, D) of zebrafish embryos from 24 to 120 hpf. (A) Mean body length in mm, and (B) trunk–tail angle in degrees, of control (n=50) and arecoline-treated (n=50) zebrafish embryos examined at 24, 48, 72, 96, and 120 hpf. Zebrafish swimming patterns (C) and their swimming distance (D) in mm of the control (n=10) and arecoline-treated larvae (n=10) at 120 hpf. (*p<0.05).