Seafood includes products from water-living animals, such as fish, crustaceans, and mollusks.
Meat from cetaceans (whales and dolphins) might or might not be regarded to be seafood. By a stretch of the definition, swimming land animals such as beaver or otter have been regarded to be seafood by some Christian congregations, to be eaten during lent. They are not usually included with the concept.
Travellers might want to avoid certain endangered species; see animal ethics.
Many aquatic animals are called "fish" in English, such as jellyfish or starfish.
Animals known to common man as "fish" are however paraphyletic; they are not more closely related to each other than they are to humans or other mammals. The vast majority of species known as "fish", including most culinary fish, are however ray-finned fish (Actinopterygii). Cartilaginous fish include sharks and rays, and lobe-finned fish include coelacanths and lungfish.
In culinary terms, there is difference between fatty fish (salmon, trout, mackerel, eel, herring) and lean fish (pike, perch, cod, etc).
Roe or caviar are fish eggs, an expensive delicacy.
Lobster, shrimp and crabs are classical delicacies. The price varies a lot.
Octopus, squid, oysters and clams might disgust some people, and tempt others.
Fishing is the catching of fish and other moving water animals. Foraging might a more appropriate term for catching of immobile animals, such as clams. In most countries, fishing and foraging are restricted, if allowed at all.
In contrast to meat, which needs to be properly hung before consumption, seafood should be eaten as fresh as possible. Even though a supermarket or a restaurant is at the waterfront, there is no guarantee that the fish is fresh.
Fish should be properly cooked, for taste and food safety. For most fish, there is no "rare" or "well done".
The exception is cured fish, which has been taken care of by chemicals, instead of heat. Fish gets more tender with sour condiments, such as citrus fruit or vinegar.
Destinations and cuisine
See animal ethics.