The nerve-numbing toxin intensifies in the food chain. By the time larger reef fish, including barracuda, grouper and amberjacks swoop in for dinner, it is potent and potentially lethal - not to the big fish, but to humans who may eat them. Again, the agent is insidious - odorless, colorless, tasteless and unaffected by cooking or freezing. Sometimes there are lingering nerve dysfunctions. Hot things taste cold.
Cold things taste hot.
Ice cream will feel hot on the tongue. A city ordinance in Miami bans the sale of barracuda. In Hawaii, ciguatera is enough of a problem that a University of Hawaii professor developed a chemically treated stick to test fish flesh. The stick changes color in the presence of the toxin. In severe cases, there is difficulty walking and breathing.