Aquarium basically, is a receptacle for maintaining aquatic organisms, either freshwater or marine, or a facility in which a collection of aquatic organisms is displayed or studied.The earliest known aquarists were the Sumerians, who kept fishes in artificial ponds at least 4,500 years ago; records of fish keeping also date from ancient Egypt and Assyria. The Chinese, who raised carp for food as early as 1000 BCE, were probably the first to breed fish with any degree of success. Their selective breeding of ornamental goldfish was later introduced to Japan, where the breeding of ornamental carp was perfected. The ancient Romans, who kept fish for food and entertainment, were the first known marine aquarists; they constructed ponds that were supplied with fresh seawater from the ocean. Although goldfish were successfully kept in glass vessels in England during the middle 1700s, aquarium keeping did not become well established until the relationship between oxygen, animals, and plants became known a century later.Prior to the middle of the 19th century, the term aquarium was applied in botany to describe a container used for growing aquatic plants. Although French-born naturalist Jeanne Villepreux-Power invented the first recognizable glass aquarium in 1832, it was in the works of British naturalist Philip Gosse, however, that the term first took on its modern meaning as a vessel in which aquatic animals, as well as plants, can be held. His work aroused increased public interest in aquatic life. By 1850 the keeping of fishes, amphibians, and reptiles had become useful in the study of nature.The first display aquarium was opened to the public in 1853 at Regent's Park in London. It was followed by aquariums in Berlin, Naples, and Paris. P.T. Barnum, the circus entrepreneur, recognized the commercial possibilities of living aquatic animals and, in 1856, opened the first display aquarium at the American Museum in New York City as a private enterprise. By 1928 there were 45 public or commercial aquariums throughout the world, but growth then slowed and few new large aquariums appeared until after World War II.Many of the world's principal cities now have public aquariums as well as commercial ones. Another category encompasses those aquariums that serve chiefly as research institutions. Among the best known of the latter are those at Naples; the Oceanographic Museum of Monaco; Plymouth Marine Laboratory, Eng.; and Scripps Institution of Oceanography, La Jolla, Calif. Still another category includes temporary aquariums that have served as exhibits at world's fairs and expositions.In 1938 the first oceanarium, or large marine aquarium, Marineland, opened near St. Augustine, Fla., as a private enterprise; it featured a giant community fish tank and trained dolphins. The Seaquarium, Miami, is similar. The emphasis in this type of aquarium is on very large tanks, up to 1,000,000 gallons each, in which a great variety of fishes is placed with no attempt to separate them. In the formal aquarium (e.g., the Shedd Aquarium, Chicago), the kinds and types of fishes are separated in most of the exhibits.