Fish is consumed as a food by many species, including humans. It has been an important source of protein and other nutrients for humans throughout recorded history.

In culinary and fishery contexts, the term fish can also include shellfish, such as molluscs, crustaceans and echinoderms. English does not distinguish between fish as an animal and the food prepared from it, as it does with pig vs. pork or cow vs. beef. Some other languages do, as in the Spanish peces versus pescado. The modern English word for fish comes from the Old English word fisc (plural: fiscas) which was pronounced as it is today. English also has the term seafood, which covers fish found in the seas and oceans as well as other marine life used as food.

Species

Over 32,000 species of fish have been described, making them the most diverse group of vertebrates. In addition, there are many species of shellfish. However, only a small number of species are commonly eaten by humans.

Preparation

Fish can be prepared in a variety of ways. It can be uncooked (raw) (cf. sashimi). It can be cured by marinating (cf. escabeche), pickling (cf. pickled herring), or smoking (cf. smoked salmon). Or it can be cooked by baking, frying (cf. fish and chips), grilling, poaching (cf. court-bouillon), or steaming. Many of the preservation techniques used in different cultures have since become unnecessary but are still performed for their resulting taste and texture when consumed.

Aquarium fish feed is plant or animal material intended for consumption by pet fish kept in aquariums or ponds. Fish foods normally contain macro nutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately 80% of fishkeeping hobbyists feed their fish exclusively prepared foods that most commonly are produced in flake, pellet or tablet form. Pelleted forms, some of which sink rapidly, are often used for larger fish or bottom feeding species such as loaches or catfish. Some fish foods also contain additives such as sex hormones or beta carotene to artificially enhance the color of ornamental fish.

Prepared foods

Prepared foods are those foods that are non-living and are made by the aquarist or bought already prepared for consumption for fish.

Dry foods

Flake food is a type of proprietary or artificially manufactured fish food consumed by a wide variety of tropical and saltwater fish and invertebrates. It is ideally suited to top dwellers and mid-water fish though numerous bottom dwelling species consume flake food once it has settled on the bottom. Flake food is baked to remove moisture, ensuring a longer shelf life. Generally the more moisture a particular example of fish food contains, the more readily it will deteriorate in quality.