Ciguatera

Ciguatera is a foodborne illness caused by eating certain reef fish whose flesh is contaminated with a toxin made by dinoflagellates such as Gambierdiscus toxicus which live in tropical and subtropical waters. These dinoflagellates adhere to coral, algae and seaweed, where they are eaten by herbivorous fish which in turn are eaten by larger carnivorous fish like barracudas, and even omnivorous fish like basses and other fish like mullet. This is called biomagnification. It is not known why the fish are not affected.

Gambierdiscus toxicus is the primary dinoflagellate responsible for the production of a number of similar polyether toxins, including ciguatoxin, maitotoxin, gambieric acid and scaritoxin, as well as the long-chain alcohol palytoxin. Other dinoflagellates that may cause ciguatera include Prorocentrum spp., Ostreopsis spp., Coolia monotis, Thecadinium spp. and Amphidinium carterae.Predator species near the top of the food chain in tropical and subtropical waters are most likely to cause ciguatera poisoning, although many other species cause occasional outbreaks of toxicity.

Ciguatoxin is odourless, tasteless and cannot be removed by conventional cooking.