I reckon this is why Cod is never eaten raw?

Potential Parasites

Parasites are a fact of life when you eat meat. That's one reason why humans decided to start cooking their food thousands of years ago. Heat kills worms. So does frost, but some can survive a home freezer (although not a good box freezer).

For this reason, it is recommended that all seafood you decide to eat raw be previously frozen. It is simply safer that way. Yes, fresh is better in most cases, but even professional sushi chefs freeze their salmon first—salmon is unusually susceptible to parasites.

The critters you need to worry about are cod worms, seal worms, and tapeworms.

Cod worms are found in cod, haddock, pollock, and hake. They are easily visible to the naked eye and are easily removed if you catch them. Good New England fish houses "candle" their fish by putting the fillets on a lightbox to detect the worms. This is why cod is never seen at a sushi bar.

Ref: https://www.thespruceeats.com/choosi...-sushi-1300689