Rainbowfishes are small, colourful freshwater fishes belonging to the family Melanotaeniidae, found in northern and eastern Australia, New Guinea, Sulawesi and Madagascar.

The eastern mosquitofish is a species of freshwater fish, closely related to the western mosquitofish, Gambusia affinis. It is a member of the family Poeciliidae of order Cyprinodontiformes. The eastern mosquitofish is native to the eastern and southern United States from Florida to Pennsylvania and inland to Alabama and Tennessee, while the western mosquitofish has a larger distribution throughout the United States.