Knowing how to choose fresh fish or seafood is a vital skill for a seafood cook. Unless you caught the fish yourself, you need to check the signs to ensure it's fresh. Buying fresh fish is easy if you know what to look for.
Look for bright, clear eyes. The eyes are the window to a truly fresh fish, for they fade quickly into gray dullness. Dull-eyed fish may be safe to eat, but they are past their prime. Next, look at the fish. Does it shine? Does it look metallic and clean? Or has it dulled or have discolored patches on it? If so, it is marginal.