Chloropicophyceae (Prasinophyte Clade VII) are small nonmotile coccoid cells with cell diameters ranging from 1 to 3 μ m. Molecular surveys indicate they are relatively high in abundance in moderately oligotrophic oceanic waters and may substantively contribute to biogeochemical cycling in the sea. Here, we quantify the elemental and macromolecular composition of three subtropical Chloropicophyceae strains: Chloropicon mariens...