Authors first examined the morphology of axial skeleton of the yellowfin tuna to develop the experimental equipment for destroying the central nervous system, and then examined the work ability of this equipment. The results are as follows.
A stainless wire rope of three millimeters in diameter is the most efficient for destroying the central nerve for insertion into the vertebral foramen and removal using a winding drum as in the second experimental equipment.
Efficiency of destruction of the central nerve by the second experimental equipment is improved by increasing velocity by raising the output voltage.
Total resistance Rt for destroying the central nerve is in proportion to the diameter of the steel wire, fish size, diameter of the spinal cord, the total time passed while inserting steel wire, the level of viscosity of mucus in the cranium and the vertebral foramen. Fish size is the strongest factor.