Fig. 4.

(A) Effect of chain formation and swimming speed on encounter rate (maximal clearance) with an ambush predator (v_predator = 0, Eq. 1). Values for single cells and chains from the ungrazed control (open circles) and the grazed treatment (red triangles) are shown. (B) The effect of predator velocity on encounter rates for single cells and chains (Eq. 1) from control (black) and grazed (red) treatments normalized to the encounter rate of single cells in the control treatment for comparison. The difference in encounter rate is highest for ambush predators where v_predator = 0 and decreases with increasing predator velocity toward the difference solely driven by the difference in reaction distance, i.e., 2.2 and 4.6 times higher for two- and four-cell chains, respectively, compared with single cells. Typical swimming velocities for the copepod predator used here are indicated by the shaded box labeled Centropages (45).