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TABLE 1. Calculation of the Re in the most distal (aboral) portion of the hydrospire, corresponding to the first eight hydrospire pores, in living Pentremites rusticus and in the 72x scale model.

  Pentremites rusticus Model
  If the cilia are in pore canals If the cilia are in the folds
Pore canal parameters      
       Pore diameter, m 25.4x10-6 25.4x10-6 1.85x10-3
       Pore area, m2 5.1x10-10 5.1x10-10 2.69x10-6
       Pore velocity, m/s 6.0x10-4 † 0.040 3.2x10-3
       Volumetric flow rate, m3/s 3.0x10-13 2.0x10-11 6.9x10-8
Hydrospire fold parameters      
       Fold spacing, m 4.3x10-5 4.3x10-5 0.0031
       Distance between adjacent pores, m 2.65x10-4 2.65x10-4 0.0153
       Area of folds between adjacent pores, m2 3.4x10-8 3.4x10-8 1.42x10-4
       Hydraulic diameter, m 8.6x10-5 8.6x10-5 0.0062
Velocity in folds, m/s 9.0x10-6 6.0x10-4 † 61x10-6
Kinematic viscosity, m2/s 1.8x10-6, 0°C seawater 1.8x10-6, 0°C seawater 1.0x10-6, 25°C freshwater
  9.4x10-7, 25°C seawater 9.4x10-7, 25°C seawater  
Reynolds number in folds 0.0004 at 0°C 0.03 at 0°C 0.376
0.0008 at 25°C 0.05 at 25°C
† Cilia velocity from (Paul, 1978)