All over the United States today, large and small Japanese food stores carry a variety of sushi fish. Some of these stores are listed in the appendix (“Sources for Japanese Food Products”); you may find others in the phone book or on the Internet. Fish fillets and blocks are packed in Styro-foam trays with plastic lids or wrap and an expiration or sell-by date. The packages of sushi fish are stored in a refrigerator case separate from fish meant for cooking. If you’re not sure what fish is for sushi, just ask. If you want a whole fish rather than a piece, your fishmonger should be able to provide it, but be sure to tell him or her that you want the fish for sushi.