There is an old saying that "fish is the sweeter for having been hunted." But the best assurance of superb cooking quality is the utmost freshness of the fish.

This time of year, gentler weather permits more fishermen to ply Chesapeake and tidal river waters, and markets should be filled with a wonderful display. Fish is always a delicate change from the monotony of a meat heavy diet. And in addition to sole, salmon, swordfish, flounder, mackerel, and others generally found at a good market, fish from nearby waters adds a touch of seasonal zest to meals.

Here are few of the fish from Tidewater areas that we can find at the local fishmongers:

Shad is a traditional favorite, available here in late March, April and May. The shad comes into tidal creeks to spawn. The female, called a "hen shad" in local terminology, is more desirable; it is larger, fatter and provides both fillets and that famous culinary delight, shad roe. To many, the only way to prepare shad is to bake it, but shad fillet is excellent if the fish is large enough, and if it is filleted skillfully. Anyone who has bitten into poorly boned shad will never forget the sensation. But the problem of shad bones can be largely eliminated if the fish is baked at low heat a long time. "Buck," or male shad, though less meaty, is equally tasty.

Some people are disdainful of the croaker, considering it a "common" fish. How sadly mistaken they are. The Atlantic croaker, or hardhead, is a member of the Drum family. When caught, it makes a peculiar croaking noise that might account for the squeamish attitude of some. The croaker has lean, white meat, usually weighs from 1/2 to 3 pounds, is sold pan-dressed, and is the mainstay of the old-time fishfry. (Fish fried with care is one of life's great pleasures, and will not disturb the most delicate digestion.)

Later in the season, another fish appears that is "kin" to the croaker: the spot. Smaller than the croaker, it is shorter and deeper and another fine candidate for the fishfry.

Then there is the northern weakfish, or trout. The weakfish got its unfortunate name because of its fragile jaw. A hook pulls from its jaw easily, as many a frustrated fisherman will attest. It is firm-textured, lean and sweet-flavored. All fish should be iced at one when caught, but the weakfish is particularly susceptible to diminished quality if it is not iced immediately. Even on ice, it should be taken to kitchen with all possible haste. It freezes quite well, and a frozen weakfish is preferable to one that has lingered on ice.

White perch enter Chesapeake waters in large spawning runs in spring and early summer, and are caught in large numbers by both commercial and sport fishermen. White perch can grace the table in many forms, adapting to all cooking methods. The white flesh and delicate flavor will be treated with imagination by creative cooks. Many people prefer the roe of white perch to shad roe.

The bluefish appears early and stays in season right into fall. Bluefish is soft-fleshed and pungent. Blues up to 6 or 8 pounds are fine for fillets or baking, but the black line down the fish should be removed. Because of its more pronounced flavor, bluefish takes well to a neutralizing combination with tomatoes or lemon juice. However, while the favor may be strong when the fish is hot, when it is cold, the flavor is much lighter and often better. Blues are a poor choice for poaching or chowders, as the flesh shreds and the flavor blend is not always agreeable. Treat it with care, however, and the bluefish is superb. Even a 10-pounder is grand, if it baked.

The striped bass or rockfish, as Tidewater residents call it, is regarded by many as the king of all fish. The "rock" is valued for the pleasure it provides sport fishermen, as well as for its exceptional palatability. This magnificent fish is probably best in the 6 to 8 pound range though some prefer them smaller. Over 8 pounds, the flesh is apt to be somewhat coarse. But large striped bass can be cut into steak for broiling and flaked for salad.

For those who go to the fish market and stare through a glass case at a multitude of fish on ice, here are a few guidelines. Ask the fish man to bring the fish out where you can have a close look at it. An honest fish man will be happy to do this and probably will be pleased with your interest. Look at the fish. Check the gills. They should be reddish-pink and clean. Never take a fish that has pale gills, dull, sunken eyes, or a flaccid belly. Also watch out if it is exceptionally dry and the flesh is not firm to the touch. A fresh fish will have glossy, bulging eyes, it will glisten and the flesh will spring back when pressed. Fresh fish has no unpleasant odor, only the clean fresh smell of salt air.

In general, allow 3/4 pounds of dressed whole fish per person. When buying fish fillets, 1/2 pound per person is the usual allowance.

The cooking method should be determined by the fat content of the fish. Fat fish are best for baking, broiling or planking because their fat content prevents their becoming dry when cooked. Lean are best for poaching and broiling because their flesh is firm. Both fat and lean fish can be fried. Both fat and lean fish can be fried. However, almost any fish can be prepared by any method, if adjustments are made in the amount of fat used in preparation. It is impossible to list all the varieties of edible fish, but some of the fish in the fat group are:

bluefish, mackerel, porgies, sea bass, shad, striped bass and swordfish. In the lean group are croaker, white or yellow perch, flounder, red snapper and weakfish.

No matter what method of cooking is called for in a recipe, it will invariably say that the fish is done when it "flakes easily." But do not poke the poor thing mercilessly with a fork, setting the juices free and turning it to tatters. Use a thin skewer for the probing to see if the flesh is coming loose from the bones and flakes readily. It works fine and is easier on the appearance.

Whether you hang out the "gone fishing" sign, or just go to the market, here are some recipes for the bounty of the sea.

FIN FISH RECIPES

Striped Bass

(4 servings) One 4-pound striped bass, boned, and left open like a book 1 cup sweet red Bermuda onions, sliced as thinly as possible 2 small lemons, sliced as thinly as possible 3 medium-sized red-ripe tomatoes, peeled and thinly sliced 1/2 cup Italian parsley leaves only, finely minced 1/4 cup fresh basil, finely chopped, or 1 teaspoon dried Salt and freshly ground white pepper to taste 1/4 cup fine Italian olive oil 1 cup dry white wine or dry vermouth

Have the fish man bone the striped bass but leave the fish whole so that it may be stuffed. Place fish in a lightly oiled oven-proof baking dish. Open the fish and layer with half the onions, lemons, tomatoes, the fresh parsley and basil. Add salt and freshly ground pepper and drizzle with half the oil. Close the fish and cover with the remaining vegetables, herbs, and lemon. Drizzle on the remaining oil and pour dry white wine or vermouth over all.

Bake at 375 degrees for 25 to 30 minutes, basting several times with the pan juices.

BROILED BLUEFISH

After removing dark midline and skin from bluefish filet, then sprinkle liberally with lemon or lime juice about 30 minutes before cooking. Salt and pepper to taste, then dot with pats of butter. Add more butter at the halfway point in cooking, and color the filet with sweet paprika. Cook under low heat for 5 minutes and under high heat for an additional 6 minutes, or until fork tender. Serve with a garnish of chopped parsley and wedges of citrus.

FISH AND SAUSAGE ROLLS

(6 servings) 6 fillets of fish 6 link sausages 1 egg, beaten 1 tablespoon lemon juice 1/2 teaspoon scraped onion 1 cup fine dry bread crumbs 2 tablespoons melted butter 2 tablespoons soup stock

Wipe filets with damp cloth. Force sausage from casing and spread over fish in a thin layer. Roll fish up, fasten with a toothpick, dip in combined egg, lemon juice and onion, and roll in crumbs. Place in greased baking pan and add melted butter and stock. Cover and bake 400 degrees for 35 minutes.

POACHED FISH

Put 2 inches of water in a skillet and simmer 1 bay leaf, 1 teaspoon onion, and 1 teaspoon salt. Add fresh fish filets from the Lean Group and poach gently (do not boil) and cover and cook until white (about 15 minutes.) Serve with melted butter.

OUTDOOR FISH STEW

(6 to 8 servings) 1/2 pound of bacon 3 pounds firm fish (shad, flounder, rock) steaked 3 to 4 inches 3 1/2 pounds of potatoes, sliced 3 1/2 pounds onions, sliced 3 large cans stewing tomatoes (enough to cover) 1 hot red pepper (or less to taste) Salt, pepper 1 large black iron pot

Fry bacon strips in the large black pot, retaining all grease and meat. Layer potatoes, onions, fish; salting each layer well. Cover with tomatoes and add hot pepper. Simmer over open fire, never allow to boil; vegetables and fish will tear up resulting in fish muddle instead of stew. Just before serving, check seasoning. To be as its best, this process should take several hours, probably about 3. Taste test as it cooks.

The stew is hearty and requires few accompaniments. CAPTION: Pictures 1 and 2, no caption