It is no surprise that cooks are serving more fish than ever before. Fish is versatile, delicious and nutritious. It also cooks quickly. Although there are literally hundreds of species of fish, only a small number are readily available across the country.

Fresh fish are generally separated into two categories, lean and fatty. Lean fish contain from 1 to 5 percent fat. Fatty fish contain from 5 to 35 percent fat, which makes their flesh darker, richer and stronger tasting than lean fish. The type of fish is an important factor when preparing and cooking fish. For an easy reference to types of fish, their availability and preferred cooking methods, refer to the Fish Chart (in Index).

Fish come in various forms. The most readily available forms of fish are whole, dressed, pan-dressed, fillets and steaks. Fillets and steaks are a good choice for inexperienced cooks.

• Whole fish are sold with the head, tail, fins and scales intact and must be gutted before cooking. These are the most economical, but they are best left to experienced cooks.
• Dressed fish are gutted and scaled with the head, tail and fins intact.
• Pan-dressed fish are dressed and have the head and tail cut off so that the fish fits into a skillet.
• Fillets are sold boneless and may or may not be skinless.
• Steaks are the cross sections from large, round fish (fish with rounder bodies and eyes on both sides of the head). Steaks vary from 3/4 to 1 inch in thickness. They contain part of the backbone, and the outside edge is covered with skin.

It is important to know what to look for when purchasing fresh fish. One can find fresh fish at most large supermarkets or at a retail fish market. An independent retail fish market usually buys its fish on a daily basis, whereas chain stores order in large quantities and often do not receive daily shipments.

When buying whole fish, look for bright, clear and protruding eyes rather than dull, hazy sunken ones. The skin should be moist and shiny, the gills red or pink and the flesh firm and elastic. A fresh fish should have a mild, slightly oceanlike odor rather than a fishy or sour smell.

Fish fillets and steaks should have moist flesh that is free from discoloration and skin that is shiny and resilient. Again, if the fillet or steak has a strong odor, it is not fresh.

Frozen fish should have its original shape with the wrapper intact. There should be no ice crystals, visible blood or discoloration on the skin and flesh. Do not allow frozen fish to thaw on the way home from the store.

When storing fresh fish, wrap it tightly in plastic wrap. If possible, place the package on ice and store in the coldest part of the refrigerator. Be sure that melting ice drains away from the fish. If the flesh comes in contact with moisture, it may become discolored. Fresh fish should be used within a day.

The most common methods of cooking fish are pan frying, deep-frying, sautéing, poaching, broiling, grilling, baking and microwaving.

Before cooking, rinse fish under cold running water and pat it dry with paper towels. Fish cooks quickly. Be careful not to overcook it as this makes the fish tough and destroys flavor. Fish is done when the flesh turns opaque and begins to flake easily when tested with a fork. Cooking times vary with each fish and cut. The following is a guideline for cooking times:

• 10 minutes per inch of fish
• 15 minutes per inch of fish cooked in a sauce
• 20 minutes per inch of frozen fish