(A) Images of an individual zoospore swimming with two flagella beating in sinuisoidal waveform shapes and its cell body gyrating with rate while moving forward with speed . The combined motion results in a helical swimming trajectory with pitch and radius . (B) Schematics showing the gyration of the cell body. (C) Theoretical model of a zoospore translating in a 2D plane using Resistive Force Theory. (D) The dependence of translational speed on the type-1 mastigoneme density (). The range of with symbol (⋆) indicates the values measured by TEM. (E) The effects of beating frequencies of the two flagella, f1 and f2, on zoospore speed , (F) power consumption of each flagellum , (G) total power consumption of two flagella (), (H) power distributed to the anterior flagellum and (I) propelling efficiency of both flagella η. In these plots, is set at 13 .