Genus Xyphophorus is a category of freshwater fish that belongs to the family of livebearers, Poeciliidae. Xyphophorus is derived from the Greek word 'xyphos', which means "sword," and 'phoros', which means "bearing." These fish are commonly known as swordtails due to their elongated lower caudal fin rays, which resemble a sword. There are various synonyms used for the Genus Xyphophorus, including Xiphophorus, Xiphophorus Günther, and Xipho. These synonyms are used interchangeably to refer to swordtail fish which are native to Central America and Mexico. Swordtails are a popular choice among aquarium enthusiasts due to their colorful appearance and ease of care.