About Xiphophorus maculatus (Günther, 1866)
Xiphophorus maculatus, commonly called the southern platyfish, common platy, or moonfish, is a species of freshwater fish belonging to the family Poeciliidae of the order Cyprinodontiformes. This species is a live-bearer, and is closely related to the green swordtail (X. hellerii), with which it can interbreed. It is native to parts of North and Central America, ranging from Veracruz, Mexico, to northern Belize. Southern platyfish reach a maximum overall length of 6.0 cm, or 2.4 inches. Sexual dimorphism in the species is slight: males have a more pointed caudal fin, and the male anal fin has evolved into a gonopodium, a stick-shaped organ used for reproduction. In contrast, the female southern platyfish's anal fin is fan shaped. Wild-colored varieties of X. maculatus are drab, and lack the distinctive dark lateral line that is common to many Xiphophorus species. X. maculatus prefers slow-moving waters in canals, ditches, and warm springs. The species is omnivorous, and its diet includes both plants and small crustaceans, insects, and annelid worms. Fish breeders have developed a wide range of color varieties, including orange, red, yellow, red/black, and black/white. These captive varieties are common aquarium fish kept by hobbyists. The species is often referred to simply as the platy, with the plural form platys or platies; this common name comes from the fish's original classification in the genus Platypoecilus.