Zooplankton size variation:
1) picoplankton - measure less than 2 micrometers
2) nanoplankton - measure between 2-20 micrometers,
3) microplankton - measure between 20-200 micrometers,
4) mesoplankton - measure between 0.2-20 millimeters,
5) macroplankton - measure between 20-200 millimeters,
6) megaplankton - measure over 200 millimeters (almost 8 inches).
