Fish

The word fish has several senses:

• A poikilothermic water-dwelling vertebrate with gills, specifically "bony" fishes of class Osteichthyes, "cartilaginous" fishes of class Chondrichthyes, as well as various groups of "jawless" fishes, including lamprey and hagfish.. Other aquatic animals like jellyfish and cuttlefish are not truly fish. Some species of fish have been domesticated and are kept in an aquarium.
• The flesh of a fish (in the primary sense above) used for food. May also include the flesh of other water-dwelling animals such as mollusks or crustaceans (commonly called shellfish).
• (As a verb) To attempt to catch fish for the purpose of food or sport. See fishing.

See also:

• Freshwater aquarium fish species
• Deep Sea Fishes