Both Haraguchi and Herron point out that, in certain cultures, fish has long been served raw despite never having been frozen at all, and neither was bothered by the idea of eating fish under those circumstances (though they stress that the fish they sell for raw consumption has been frozen according to FDA guidelines). Of parasites, Haraguchi says, “It’s natural. Parasites are as natural as seeing a ladybug in farmers market vegetables.” When I tell Herron that I myself have purchased fluke at The Lobster Place, butchered it, and eaten it raw at home, he says, “I’ve done the same thing. I’m fine, you’re fine. And everybody was doing that before these regulations came out, and everyone was okay.”
Dr. Judy Sakanari, a parasitologist in the Department of Pharmaceutical Chemistry at the University of California, San Francisco, believes that this view downplays the risks of ingesting anisakids. “Infection by these parasites can be very serious and can lead to resection [surgical removal of part of an organ] of the intestine,” she warns. Sakanari stresses that understanding the life cycle of the parasite is necessary to a full appreciation of the risks involved.
All parasites seek to reach their end-host organisms. For tapeworms, these are bears and other fish-eating mammals; for anisakids, they’re marine mammals, such as whales, seals, and dolphins. If all goes as the parasite gods intend, fish carrying infectious worm larvae will be consumed by an end-host organism. But if those fish are snatched up in a trawler or caught on a line, the ideal parasitic life cycle is interrupted. As soon as the fish’s body temperature begins to rise to that of the end-host mammal, the parasite larvae in its gut will attempt to find a way out, leading them to burrow into the fish’s flesh. This is one reason why it’s always best to keep ungutted fish cold: Any parasite larvae in the fish gut will remain immobile as long as the temperature is sufficiently low.
