Fig. 5. Dose–response and arousal time-courses used for simulation modeling of male N. succinea swimming responses to CSSG. (A) Dose–response relationship for speed arousal. The equation used was speed=50+(180–50)/{1+10^[(–7–log[CSSG])^*0.6]}. (B) Time-course of arousal and duration of the response, as a percentage of the maximum response to the encountered CSSG stimulus. The equation used was %=130^*[1–EXP(–time)]^3^*EXP(–time/20). (C) Dose–response relationship for turning arousal. The equation used was angle s^–1=(750)/{1+10^[(–7–log[CSSG])^*0.6]}. (D) Time course of arousal and duration of the turning response, as a percentage of the maximum response to the encountered CSSG stimulus. The equation used was %= 100^*[1–EXP(–time/0.05)]^3–[1–EXP(–time/0.05)]^*[1–EXP(–time/0.5)]^25. The preceding formulae are written with Excel spreadsheet functions and operators, where EXP() means e raised to the power in the parentheses, ^ means exponential and ^* means multiplication.