Numerical reconstruction of swimming paths. Model Ca²⁺ signals and corresponding reconstructed paths using the fit parameters κ₁ and β of Eq. 1. The swimming speed was considered constant for simplicity (v = 200 µm/s). (A) The slope of the rising phase (Ca²⁺ influx) determines the sharpness of the chemotactic turn and the orientation of the cell after the turn. (B) The length of the rising phase determines the duration of the turn and, therefore, codetermines the orientation of the cell before the run. (C) The slope of the Ca²⁺ decline determines the length, the straightness, and sign of the curvature during the run period, depending on the parameters κ₁ and β. (D) The kinetics of the rising and declining phases and the amplitude of the Ca²⁺ signal determine the drifting speed and direction of circles.