Describes fish of the mackerel family (Scombridae), including tuna, mackerel, and bonito, and, in food-safety contexts, the histamine poisoning these fish can cause when mishandled.
Scombroid fish contain naturally high levels of the amino acid histidine, which bacteria convert to histamine if the fish isn't chilled quickly after being caught; eating fish in this state causes scombroid poisoning, with symptoms resembling an allergic reaction (flushing, headache, cramping) that can appear within minutes of eating. Properly caught and refrigerated scombroid fish pose no unusual risk and are valued for their firm, oily, flavorful flesh — tuna is used raw in sushi and sashimi as well as grilled or canned, while mackerel and bonito are often smoked, grilled, or used in stews and curries. Because histamine isn't destroyed by cooking, the poisoning risk depends entirely on how quickly the fish was chilled after catch, not on how it's later prepared.