Authorities in the central Japanese city of Gamagori activated an emergency warning system Tuesday in a bid to prevent residents eating parts of potentially deadly pufferfish that were mistakenly placed on supermarket shelves. Pufferfish, or fugu, is an expensive delicacy often served in the form of paper-thin sashimi slices. But the fish’s skin, intestines, ovaries, and liver contain the poison tetrodotoxin, which is 1,200 times deadlier than cyanide.