What's the difference between sushi quality (or grade) fish and non-sushi quality (grade) fish?

Question

What's the difference between sushi quality (or grade) fish and non-sushi quality (grade) fish?

Answer 1

Sushi quality is fish that has the ULTS (Ultra Low Temperature Seafoods) logo (-75C) or Super Frozen on their packages. These fish have been processed immediately after being caught. This ensures the color, taste and texture remain intact. They are considered fresher than fresh.

Fish, which you normally find at your local market, are not sushi grade. They are great for cooking, but not to be eaten raw.

Answer 2

sushi quality can be eaten raw.  Non-sushi quality must be cooked first.  It is not FDA regulated, so there is no official definition.

Answer 3

Freshness and the location of the cut on the fish. Since it is served raw the preferred area of the fish is the tail since it is the most firm (fish muscles)...There is a big difference in the different parts of tuna and salmon. Others I don't know about. I'm sure a knowledgeable Japanese person is on their way though...