Fig. 6. Simulated behavior of male N. succinea in response to various concentrations of CSSG. The direction and starting point of the worm in the simulation is shown by the yellow arrow in each illustration; the trajectory of the worm is indicated by the narrow black line; the simulated final position of the worm when the simulation was terminated is shown by the short black line; and the dispersion of pheromone by the simulated swimming of the worm through it is shown by the spread of the blue color of the initial line of pheromone (initially approximately 7 mm wide). Concentrations of pheromone in the simulated `trail' initially were (A) 0 (control, no pheromone), (B–D) log[CSSG]=–8.5 (i.e. 3.16x10^–9 mol l^–1), (E) log[CSSG]=–8.0 (i.e. 10^–8 mol l^–1), and (F) log[CSSG]=–8.5 (i.e. 3.16x10^–8 mol l^–1). The 10 cm calibration applies to all parts.