A small freshwater fish of South America and West Indies (Lebistes reticulatus or Poecilia reticulata, originaly called Gerardinus guppyi), often kept in aquariums; also called rainbow fish.
The guppy , also commonly known as guppie, is one of the most popular freshwater aquarium fish species in the world. It is a small member of the Poecilidae family (females 4 centimetres long, males 2½–3 centimetres long) and like all other members of the family, is live-bearing. It prefers a hard water aquarium and can withstand levels of salinity up to 150% sea water (58 ppt sodium chloride)Chervinski, J. (1984) Salinity tolerance of the guppy, Poecilia reticulata Peters.