The Pacific puffer fish contains tetrodotoxin, or TTX, which is found in the liver, gonads, and blood of certain species of the fish. Tetrodotoxin blocks the voltage-regulated sodium ion channels, eliminating the production of action potentials and preventing nerve cell activity. The Japanese consider the puffer fish, called fugu, a delicacy. Specially licensed chefs prepare fugu by carefully removing the potentially toxic organs. Although a mild tingling and sense of intoxication are considered desirable, improper preparation of the fish results in several deaths per year.