Another possibility for the name is the traditional method of harvesting. ""Sashimi"-grade" fish is caught by individual handline. As soon as the fish is landed, its brain is pierced with a sharp spike, and it is placed in slurried ice. This spiking is called the ikejime process, and the instantaneous death means that the fish's flesh contains a minimal amount of lactic acid. This means that the fish will keep fresh on ice for about ten days, without turning white or otherwise degrading.