Fig. 4: Optimal arrangements of cilia and feeding structures in sessile and motile cells.
From: Flow physics of nutrient transport drives functional design of ciliates
A, B Feeding flux Q and (C, D). Sherwood number Sh as colormaps over the morphospace (Ac, Af) of motile (top) and sessile (bottom) cells; darker colors indicate larger values, white contour lines indicate designs that produce same Q or Sh values, solid yellow lines indicate local optima at each Af; filled circles and squares indicate global optima of sessile and motile designs over the entire design space. Insets in (A, B): contour lines of Q = 104 in units of bodyvolume per hour for motile (purple) and sessile (blue); Insets in (C, D): contour lines of Sh = 2 for motile (purple) and sessile (blue) shows that Sh is more than doubled nearly everywhere in the morphospace. E Cell swimming speed U increases with increasing cilia coverage. Inset: swimming speed in units of bodylength per second, highlighting contour lines of 10 and 30 body lengths per second, with maximal value of 50 body lengths per second in the rightmost corner. F Force required to keep the cell attached increases with cilia coverage. All calculations are done at constant hydrodynamic power \({{\mathcal{P}}}\), cell volume \({{\mathcal{V}}}\), and Pe = 100 chosen based on typical particle diffusivity and flow speed measurements in ciliates.
