Astronotus ocellatus is a species of fish from the cichlid family known under a variety of common names, including oscar, tiger oscar, velvet cichlid, or marble cichlid. In South America, where the species naturally resides, A. ocellatus specimens are often found for sale as a food fish in the local markets.The fish can also be found in other areas, including China, Australia, and the United States. Although its slow growth limits its potential for aquaculture, it is considered a popular aquarium fish. These fish can grow as large as 18 inches in length and weight over 3 lbs..Oscars are able to rapidly alter its coloration, a trait which facilitates ritualized territorial and combat behaviors amongst conspecifics. Juvenile oscars have a different coloration from adults, and are striped with white and orange wavy bands and have spotted heads. A. ocellatus is native to Peru, Ecuador, Colombia, Brazil, and French Guiana, and occurs in the Amazon river basin, along the Amazonas, Içá, Negro, Solimões, and Ucayali river systems, and also in the Approuague and Oyapock drainages.] In its natural environment, the species typically occurs in slow-moving white-water habitats, and has been observed sheltering under submerged branches. A number of ornamental varieties of A. ocellatus have been developed for the aquarium industry. These include forms with greater intensity and quantities of red marbling across the body, albino, leucistic, and xanthistic forms. A. ocellatus with marbled patches of red pigmentation are sold as red tiger oscars, while those strains with mainly red coloration of the flanks are frequently sold under the trade name of red oscars. The patterning of red pigment differs between individuals; in the United Kingdom, one A. ocellatus reportedly had markings that resembled the Arabic word for "Allah". In recent years long-finned varieties have also been developed. The species is also occasionally artificially colored by a process known as painting. The Oscar is one of the most popular kept cichlids in the aquarium. Oscar Cichlids are rather large and moderately aggressive cichlids that are found in Peru, Brazil, and French Guiana, and also along the Amazon. Many keep one as a single residence in a tank as kinda wet pet. they will do well as a pair or small group in a large tanks. Oscars have been introduced many place for a game fish including Florida.