TABLE 1.

Total prokaryote abundance and average cell volumes of SAR11 bacteria and other prokaryotes in the Gulf of Maine, the Sargasso Sea, and North Carolina coastal waters

LocationStationAbundance (106 cells ml−1)aCell vol (μm3)b% CVc
SAR11Other prokaryotes
Gulf of Maine14.0 ± 0.700.034 ± 0.0040.033 ± 0.00164
Gulf of Maine31.0 ± 0.250.031 ± 0.0010.033 ± 0.001*49
Gulf of Maine51.1 ± 0.330.045 ± 0.0020.045 ± 0.00153
Mid-Atlantic61.0 ± 0.310.048 ± 0.0040.040 ± 0.002*57
Sargasso Sea71.4 ± 0.480.041 ± 0.0020.037 ± 0.001*59
Sargasso Sea80.9 ± 0.360.051 ± 0.0020.040 ± 0.002*48
Sargasso Sea100.4 ± 0.240.050 ± 0.0030.043 ± 0.003*46
Sargasso Sea120.5 ± .0100.044 ± 0.0030.039 ± 0.003*35
Sargasso Sea141.0 ± 0.250.048 ± 0.0030.036 ± 0.003*44
North Carolina coastal waters151.8 ± 0.610.043 ± 0.0020.034 ± 0.002*39
  • a Means ± standard deviations for 10 fields of view.

  • b Means ± 95% confidence intervals. Statistically significant differences (t test; P < 0.01) between the cell sizes of SAR11 bacteria (n = 132 to 629) and other prokaryotes (n = 257 to 2,273) are indicated (*). Cell volumes were determined from FISH samples at 10 m and did not undergo microautoradiography preparation.

  • c Coefficient of variation of SAR11 cell volume.