In ciguatera, tiny dinoflagellates are consumed by herbivorous fish, which in turn are eaten by bigger fish. The nerve-numbing toxin intensifies in the food chain. By the time larger reef fish such as 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. 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.