The Green swortail (Xiphophorus hellerii) is a species of freshwater fish in family Poecilidae of order Cyprinodontiformes. It is also called Red swordtail. A live-bearer, it is closely related to the southern platyfish or "platy" (X. maculatus) and can interbreed with it. It is native to an area of North and Central America stretching from Veracruz, Mexico, to northwestern Honduras.