There are several methods for spiking the hind-brain or bleeding the “pre-rigor ik”i or “rigor mortis shime” fish. In the case of iki fish such as Kingfish (but excepting snapper and some other fish), all live fish in the markets are cut or slit on their head with a heavy knife to isolate the hind-brain from the spinal cord.
As the spinal cord is also responsible for some autonomic reaction, fish over three kilograms are often killed by inserting wire down the spinal cord. Tuna long-liners in New South Wales are presently using similar methods to destroy the spinal cord of large tuna. On certain fish, in addition to coring, the blood vessels and arteries are slit to facilitate bleeding.
Presentation is important in shime fish, as damage to the surface of the fish should be avoided if possible by spiking through the right side, using a sharp implement which will only show a small mark on the left side. In Japan, all fish are served with their head to the left and a spike mark will therefore be positioned underneath.