Scombroid fish poisoning is an illness that results from eating spoiled (decayed) fish. It is most commonly reported with ahi (tuna), mahimahi, bonito, aku, albacore, sardines, anchovies, and related species of fish that were inadequately refrigerated or preserved after being caught. Scombroid can result from inappropriate handling of fish during storage or processing. One of the toxic agents implicated in scombroid poisoning is a chemical called histamine. Other chemicals have been found in decaying fish flesh, but their association to scombroid fish poisoning has not been clearly established.