platy

Platy commonly refers to small freshwater aquarium fish in the genus Xiphophorus. The best-known species are Xiphophorus maculatus (southern platyfish) and Xiphophorus variatus (variatus platy), both in the family Poeciliidae. They are native to Mexico and Central America and are widely distributed in the aquarium trade. This article concerns the aquarium fish, not the platypus, the egg-laying mammal.

Platies are compact, laterally compressed fish about 2–3 inches long. Males are smaller and have a pointed anal fin called a gonopodium; females are larger with a rounded anal fin. Color patterns range from solid reds or oranges to multicolored blends produced by selective breeding.

In their native habitat they inhabit slow-moving streams and ponds. In aquariums they tolerate a range of conditions but prefer stable environments. Recommended water parameters are 72–78 F (22–26 C), pH 7.0–8.0, and hardness 5–20 dGH. They are hardy and suitable for beginners.

Diet is omnivorous. In captivity they eat high-quality flakes or pellets, with occasional live or frozen foods such as daphnia or brine shrimp. They are generally peaceful and do well in community tanks, though long-finned species may experience some tail nibbling.

Platies are livebearers. Females give birth to free-swimming fry after about 28 days. Broods vary in size and fry are tiny, so many hobbyists provide hiding places or rear young separately. A common breeding setup uses more females than males to reduce stress.

Breeds include numerous color and fin varieties. There is no major conservation concern for captive platies, but some wild populations suffer from habitat loss and pollution.