Dawgluver,
Yes , I vacuum pack the fillets and freeze them for about 2 weeks.
Joe
Hey Joe, as long as your freezer maintains Minus Four Degrees Fahrenheit or lower, 7 days at that temp or lower will rid it of any of the parasites common to walleye. Vacuum packing helps extend the life of the frozen fish, but does little to counter parasites and almost nothing in the case of bacteria already present.
Using very clean handling during the cleaning and storing of the fish will help a lot with any bacterial induction.
Above Minus Four Degrees Fahrenheit, or for lesser amounts of time, and you risk infecting yourself with one of many parasites that are common to that species. Tape Worm is the most common. It won't show up after infection for as much as years. You don't want this for sure.
The preparation of ceviche does nothing to rid it of parasites. It creates an environment that will deter *more* infestation of parasites, but does virtually nothing about those already in the meat.
The acid of the citrus in ceviche preparation will make the meat *appear* to be cooked, but the meat is just as raw as when used in sushi. The cooked appearance is deceiving. It's not cooked at all.
Please make sure you freeze the meat at Minus Four Degrees Fahrenheit or lower, for a minimum of 7 days. This will kill all known parasites, (with the exception of a few very uncommon types), that are already in the meat.
You do not want to become infested with Tape Worms. The treatment is nasty, (read about it, but luckily have never had it happen).