Ciguatera
Food poisoning from eating reef fish that have built up toxins from tiny algae living on corals.
Also: ciguatera fish poisoning
Ciguatera comes from toxins made by a small single-celled alga, Gambierdiscus, that lives on seaweeds and dead coral. Grazing fish eat it, predators eat the grazers, and the toxin builds up in large reef fish such as barracuda, groupers, snappers and moray eels. Cooking, freezing or smoking does not destroy it. It causes stomach upset and odd nerve symptoms, such as feeling hot as cold, that can last weeks. It is one of the most common kinds of fish poisoning and is found across tropical reefs, including the Indian Ocean.