English: (A) Size distribution of virus, bacteria, and grazers. Virus radius relates to capsid cross-section, and bacteria and grazer values are equivalent spherical radius. Viruses include a compilation of bacteriophage (Brum et al., 2013; Jover et al., 2014) and viruses of eukaryotic algae (Brussaard, 2004; Brum et al., 2013), including the largest, “giant viruses” (Abergel et al., 2015). Bacteria are from the compilation of DeLong et al. (2010), and include a range of marine and non-marine species. Grazers are from Taniguchi et al. (2014). Frequency at each size represents the number of cultured strains, which says nothing of the relative abundance at each size, or phylogenetic contrast (Felsenstein, 2017). (B) Contrasting strategies to encounter prey, represented here with the green circle. Viruses are dependent on Brownian motion, whereas grazers must swim to find prey.

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