Green-skinned red-fleshed fish refers to a fish with blue skin, rich blood vessels in subcutaneous tissues and muscles and high hemoglobin content, which is red. This fish contains a lot of histidine. When it is polluted by bacteria rich in histidine decarboxylase and the environmental conditions are suitable, histidine will be decarboxylated in large quantities to produce histamine, and allergic poisoning will occur after eating.

Fish with green skin and red meat often produce more histamine because of the proliferation of bacteria, which will poison people after eating it. Whether histamine in fish can cause allergic poisoning to consumers depends not only on the histamine content and intake of fish, but also on whether synergistic substances are ingested at the same time.