Table 2.

Concentrations of heterotrophic and phototrophic picoeukaryotes, Prochlorococcus and Synechococcusin whole water and in the fractions passing through the prefilters for the samples used to generate eukaryotic genetic libraries

LibrarySampleConcn (103 cells ml−1) ofa:
PicoeukaryotesProchlorococcusSynechococcus
HeterotrophicPhototrophicP1P2P3
ME1Whole water 1.5 13.912.7 12.9
<5-μm fractionNDb 14.114.8 12.7
ANT37 Whole water 0.4 9.92.5 5.2 2.2 0 0
<1.6-μm fractionND 0.5 0.4 0.1 0 0 0
ANT12 Whole water 0.7 3.2 1.3 1.5 0.4 00
<1.6-μm fraction ND 1.00.8 0.2 0.0 0 0
NA11 Whole waterND 6.6 4.8 1.8 0 4.6
<2-μm fraction ND 6.6 4.62.0 0 2.6
NA37 Whole waterND 3.2 0 7.3
<2-μm fraction ND 4.60 6.8
  • a Heterotrophic picoeukaryotes were counted by the epifluorescence method, and phototrophic picoplankton (both eukaryotic and prokaryotic) were counted by the flow cytometry method. P1, P2, and P3 are distinct phototrophic picoeukaryote populations (P1 cells are smaller than P3 cells).

  • b ND, not determined.