This nematode is a white larva, 1-2 cm long, highly dangerous for our health because it migrates from the fish entrails to its meat if it is not quickly gutted after capture. It is mainly found in anchovies, sardines, mackerel, and herrings, but also in tuna, salmon, cod, mullet, seabass and swordfish, as well as squid, hake and angler fish.
At the least, once swallowed the larva will die or not induce symptoms; however it could also settle on the wall of the gastrointestinal system, from the stomach to the colon, causing an acute or chronic parasitic disease which sets in a few hours after eating raw fish.
Anisakis is also acknowledged as a possible cause of allergies that involve rashes, asthma, angioedema, rhinitis, conjunctivitis and anaphylactic shock. It is commonly treated by surgery to remove the part of the stomach or intestine to which the parasites have attached.