The anatomical basis of swimming in Whales.

Authors


Summary.

  • 1The swimming movement of whales involves a vertical oscillation of the tail and a simultaneous, independent, adjustment of the angle of the flukes.
  • 2The centres of rotation of the tail and flukes are determined by characteristics of the axial skeleton and associated ligaments.
  • 3The axial musculature is simplified to give power rather than versatility. The bulk of the epiaxial musculature is inserted into the tail by two series of long tendons and causes upward flexion; a special branch of this muscle is exclusively concerned with upward flexion of the flukes. The hypoaxial musculature is incompletely divided into two parts, one flexing the tail downwards and one flexing the flukes downwards.
  • 4No support is given by the anatomy to the sculling theory or the circularly polarized wave theory of the swimming movement.

Ancillary