Before revision: As a rule of thumb, nekton are larger andswim at biologically high Reynolds numbers ( 103 to 109 ), where inertial flows are the rule and eddies (vortices) are easily shed.
After revision: As a rule of thumb, plankton are small and, if they swim at all, do so at biologically low Reynolds numbers ( 0.001 to 10 ), where the viscous behaviour of water dominates and reversible flows are the rule and eddies (vortices) are easily shed.