Here's some good info:
[h1]
Parasites in Marine Fishes[/h1]
[font=Arial, Helvetica, sans-serif]All living organisms, including fish, can have parasites. Parasites are a natural occurrence, not contamination. They are as common in fish as insects are in fruits and vegetables. Parasites do not present a health concern in thoroughly cooked fish.[/font]
Parasites become a concern when consumers eat raw or lightly preserved fish such as sashimi, sushi, ceviche, and gravlax. When preparing these products, use commercially frozen fish. Alternatively, freeze the fish to an internal temperature of -4°F for at least 7 days to kill any parasites that may be present. Home freezers may not be cold enough to kill the parasites.
The health risk from parasites is far less than the risk from "unseen" illness causing bacteria which are present on almost all foods. Here are some commonly asked questions about fish parasites.
[h3]How long should I cook fish to kill parasites?[/h3]Cooking fish to an internal temperature of 140°F will kill all fish nematodes and tapeworms. Normal cooking procedures generally exceed this temperature.
Much More:
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http://seafood.ucdavis.edu/Pubs/parasite.htm[/font]
[font=Arial, Helvetica, sans-serif]Bear[/font]