It is said the species of fish in the world reach 30,000 to 50,000. There are 2,000 to 3,000 kinds of marine fishes and fresh water fishes among the categories for viewing. In fact, there are only about 500 kinds to be fed commonly and seen frequently.
Ornamental fish mainly includes marine fish, tropical fish, Chinese Goldfish, Koi and other fresh water fish. The volume will only introduce some common breeds divided according to custom and maybe with some discrepancies.
Tropical fish: Including characin, cyprinidae, medaka, cichlid, gourami, biota or loach and groupers and so on.
Dragonfish or Arowana: Within primitive fish and also tropical fish, but people list it sole customarily.
Discus: Belongs to cichlid of tropical fish, but divided in one as per its unique shape.
Chinese Goldfish: Originates from China as one of Chinese quintessence, but has been fostered many other new species out of China.
Koi: Bred on many countries, but the best species from Japan.
Marine fish: Rich in breeds, but only limited hundreds kinds can be fostered within tank.
Other fishes: Contains primitive fish and other fresh water fish.