The guppy (Poecilia reticulata) is a type of tropical freshwater fish belonging to the genus Poecilia in the family Poeciliidae of the Cyprinodontiformes order. It is also known as the rainbow fish, million fish, guppy fish, anchovy, etc. Adult guppies are about 3 to 5 centimeters in length, with rich colors and various caudal fin shapes, such as lyre-tail, round-tail, flag-tail, etc. The male fish has bright body colors, while the female fish is relatively plain. Guppies are gentle in temperament and easy to raise, suitable for being mixed with other gentle small and medium-sized tropical fish.
Guppies are native to the central and northern regions of South America, such as Trinidad, Venezuela, northern Brazil and the West Indies. They prefer weakly alkaline water quality and can tolerate relatively low water temperatures. They have a wide range of feeding habits, eating both animal baits and plant baits.
Guppies are widely raised as ornamental fish due to their beautiful appearance and strong reproductive ability. They give birth once a month, with each birth producing 10 to 120 fry, thus earning the good name of "million fish". In addition, guppies are also used in genetic research and medical experiments. Because of their strong ability to devour mosquito larvae, many countries and regions have introduced guppies as a means of biological control to control the reproduction of mosquitoes.