Seafood is the most abundant source of protein there is. Consider all the varieties, around the world, and it’s an immense category of food. Narrowed down to its basic parts, the world of seafood is easy to navigate.

Seafood is a name given to all marine animals caught or raised for food. This includes both fresh and saltwater species. People tend to condense them all into a general category of fish, but there are many subcategories.

Fish Groups

Fish is first divided into two basic types: finfish and shellfish.

There are two kinds of finfish: flat fish and round fish. The flat fish, which include flounder, halibut, and sole, skim along the bottom of the sea. Round fish (which only appear round if they are swimming straight toward you) are found in both fresh and salt water. The fresh water fish have much smaller bones than their larger, oceangoing cousins.

Shellfish are also separated into two categories: mollusks, such as mussels and clams, and crustaceans, which includes crabs, lobsters, crayfish, and shrimp.

Choosing Fish

If you are lucky enough to live near the sea, you will likely have an abundance of fish at your market. Further inland, your fish selection may be more limited. Luckily, frozen fish today are of very high quality, as they are flash-frozen on board the ship that caught them.

When buying frozen fish, be sure it is free of ice, which is a sign that it has been defrosted and refrozen. It should have a natural shape, with only a light coating of frost.

Defrost frozen fish slowly, 24 to 36 hours in the refrigerator is best. Place defrosting fish in a colander or perforated pan to separate the runoff juices. Smaller pieces can be cooked frozen.

When buying fresh fish, be sure that all you smell is fresh, oceany fish. If the smell is off-putting, don’t buy it. When you get it home, store it in the fridge loosely covered in paper, preferably in a perforated pan to allow juices to drain away. If the fish is stored longer than two to three days, it should be frozen.