Because of their low Re picoplanktondo not sink through the water column as individual cells; they can sink only if pack-aged into larger material (e.g., through predation, fecal pellet, and marine snow for-mation)
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due to their tiny size, all picoplankton, whether eukaryotic or prokaryotic, have low Reynolds numbers (Re), indicating that their movement is dominated by viscous forces, rather than inertial force