But there are caveats: Freshwater fish and some anadromous fish—fish, like salmon, that divide their life cycles between fresh and salt water—are susceptible to broad fish tapeworms, which are widely considered more harmful than other parasitic worms. Few experts recommend eating fish in the cod family—particularly Atlantic cod, but also Pacific cod, haddock, and pollack—since they’re highly susceptible to infection by a range of parasites. (According to Haraguchi, there’s another reason fish in the cod family are not eaten raw: “There’s so much moisture [in the flesh], it doesn’t taste good.”)
The parasites that infect most marine fish are nematodes, or roundworms, from the genus Anisakis. It’s preferable to avoid eating them, of course, but conventional wisdom says that the stray live anisakid in your gut will, at worst, provoke some discomfort—nausea and possible stomach pain, similar in kind to a bout of food poisoning.
Temperature Abuse and Bacterial Contamination: The Real Danger
Haraguchi and Herron agree that parasites in raw fish are less of a concern than bacterial contamination. “At the end of the day, we can freeze this product—so we’ve gotten rid of the worms—but you could temp-abuse it at home, we could temp-abuse it here, there’s a million different things that can impact the bacterial count on that fish,” Herron says.
