FIG 1.

Elemental composition of aquatic giant viruses and bacteriophages. Atoms of carbon (A), nitrogen (B), and phosphorus (C) per virion were derived by a size-dependent model. Color determines whether the virus infects algae (light blue; n = 29), protozoans (dark blue; n = 24), or, for comparison, bacteria (green; n = 11). The elemental ratios of C/N and N/P are displayed (D). Modified calculations for marine and freshwater NCVs are displayed in comparison to calculations for marine bacteriophages that were done using the model described by Jover et al. (28). Black shapes display selected viruses for which feeding by marine grazers has been observed, including Emiliania huxleyi virus 86 (EhV-86 [black squares]), Phaeocystis globosa virus 16T (PgV-16T [black triangles]), and Prymnesium kappa virus RF01 (PkV-RF01 [black diamonds]). For a full list, see Table S2.