Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, as a branch of agriculture.
Fish have been raised as food in pools and ponds for thousands of years. Brightly colored or tame specimens of fish in these pools have sometimes been valued as pets rather than food. Many other cultures kept fish for both functional and decorative purposes.
Ancient Sumerians kept wild-caught fish in ponds, before preparing them for meals. Depictions of the sacred fish of Oxyrhynchus kept in captivity in rectangular temple pools have been found in ancient Egyptian art.
Similarly, Asia has experienced a long history of stocking rice paddies with freshwater fish suitable for eating, including various types of catfish and cyprinid. Selective breeding of carp into today's popular and completely domesticated koi and goldfish began over 2,000 years ago in Japan and China, respectively. The Chinese brought goldfish indoors during the Song Dynasty to enjoy them in large ceramic vessels.
In Medieval Europe, carp pools were a standard feature of estates and monasteries, providing an alternative to meat on feast days when meat could not be eaten for religious reasons.
Marine fish have been similarly valued for centuries. Wealthy Romans kept lampreys and other fish in salt water pools. Tertullian reports that Asinius Celer paid 8000 sesterces for a particularly fine mullet. Cicero reports that the advocate Quintus Hortensius wept when a favored specimen died. Rather cynically, he referred to these ancient fishkeepers as the Piscinarii, the "fish-pond owners" or "fish breeders", for example when saying that ...the rich (I mean your friends the fish-breeders) did not disguise their jealousy of me.