Poisoning caused by eating fish or shellfish that have been inadequately preserved. Several types of seafood poisoning have been identified. Ciguatera, for instance, is a type of food poisoning found in tropical waters in which large fish over 6 pounds eaten by vacationers and other recreational fishermen have fed on small fish that in turn have fed on toxic microplankton. The symptoms of ciguatera begin within 6 hours of eating the toxic fish and include nausea, cramping, and vomiting, followed by headache and tingling or numbness of the lips, tongue, and mouth.