Table 1.

Kinematic and wake parameters during locomotion by Scomber japonicus at speeds of 1.2 and 2.2 FLs-1

1.2 FLs-12.2 FLs-1
ParameterHorizontalaVerticalaHorizontalbVerticalc
Stroke duration (ms)200±24119±8
Body angle to horizontal (degrees)-3±4-4±4
Vortex radius (cm)0.82±0.260.78±0.230.93±0.080.83±0.26
Distance between vortex centers (cm)5.49±0.713.25±0.666.79±1.053.54±0.49
Ring axis angle (degrees)34±1086±1327±591±7
Jet angle (degrees)67±9-3±553±12-2±4
Circulation (cm2 s-1)31±915±852±827±11
Momentum (g cm2 s-1)437±123210±1101001±157529±208
Lateral force (mN)22±665±14
Vertical force (mN)-1±1-1±2
Downstream force (mN)10±511±650±1644±17
Mean downstream force/mean lateral force0.5NA0.77NA
Total force (mN)24±711±684±1344±17
  • Values are presented as means ± S.D.

    FL, fork length.

    NA, not applicable.

  • a N=20 (five strokes from each of four fish); bN=12 (at least one stroke from each of four fish); cN=7 (at least one stroke from each of four fish).