Poeciliidae
The Poeciliidae are a family of fish of the order Cyprinodontiformes, the tooth-carps.  They live in fresh water.  Many live-bearing aquarium fish, such as the guppy, molly, platy, and swordtail are in Poeciliidae. These fish are from the United States to north of Río de la Plata, Argentina, and Africa, including Madagascar. Human beings took these fish to many other parts of the world and set them free there, so they have become invasive species.  Today, poeciliid fish live in all tropical and subtropical parts of planet Earth. People have seen fish in the genuses Poecilia and Gambusia in hot spring pools as far north as Banff, Alberta in Canada.