Platy

Looks how to spot one

Scaled, compact livebearer

A short, stocky little fish with a rounded tail that, unlike its swordtail cousins, has no long 'sword'. Females are larger and fuller bodied with a fan-shaped anal fin, while males are slimmer and smaller and carry a gonopodium, a rod-like fin used for mating. Wild fish are fairly plain, olive or silvery, with the variatus males showing dark marbling and spots.3165

Personality what they are like

Gentle, busy and sociable. Platies get along with most other calm fish of a similar size, and males are generally relaxed with one another. The only pushiness comes from males, who pursue females with great persistence.5

Daily activity how busy a day looks

Active all day, cruising the middle and upper water and picking at plants and surfaces. Planted tanks with open swimming room suit them well.51

Grooming and care the hands-on bits

Low maintenance. Keep the water clean with regular partial changes and provide dense plants, which give newborn fry places to hide. Because they breed so readily, plan ahead for the young or keep a single sex.53

Home where they are happiest

A tank with at least a 60 x 30 cm footprint (about 54 litres). Platies like hard, slightly alkaline water: pH about 7.0 to 8.2, hardness roughly 9 to 30 dGH, and temperature about 20 to 26 C (sources range from 18 to 28 C; the variatus platy tolerates cooler water than most tropical fish). In the wild they live in slow, weedy ditches, canals and warm springs with silty bottoms.51236

Food basics what goes in the bowl

An easy-going omnivore. Wild platies eat worms, small crustaceans, insects and plant matter. In the aquarium they are not fussy and accept most dried, frozen and live foods, so a good flake or pellet plus some plant-based food and occasional frozen or live treats covers their needs.175

Company who they like around

Best kept in a small group with more females than males, so that no single female gets all the male attention. They mix well with other peaceful community fish.5

The story where it all began

The southern platy was described by Albert Günther in 1866 and the variatus platy by Seth Meek in 1904. The southern platy was first placed in a genus called Platypoecilus, and the everyday name 'platy' is simply a shortened form of that old name; both fish now sit in Xiphophorus, the 'sword bearers', together with the swordtails. Platies became staples of the home aquarium, and breeders crossed the two species, and often swordtails too, to create the bright reds, yellows, blues and patterned forms sold today, so wild-type fish are hardly ever seen in shops. Platies also have a long scientific career. In 1924 Myron Gordon began genetics research at Cornell University with just six platyfish, studying how their colour patterns are inherited, and in the 1930s he drove to Mexico in a Model T Ford to collect wild fish. His collection grew into the Xiphophorus Genetic Stock Center, founded in 1939, which moved between New York institutions before settling at Texas State University in 1992. The southern platy's full genome was sequenced in 2013.72458

Recognised by the official bits

IUCN Red List

Xiphophorus maculatus assessed as Data Deficient (April 2018)1

IUCN Red List

Xiphophorus variatus assessed as Least Concern (March 2018)2

Taxonomy

Family Poeciliidae, genus Xiphophorus; the platies form one of three natural groups in the genus alongside the northern and southern swordtails4

Texas State University IMLS (former Xiphophorus Genetic Stock Center)

Keeps 24 of the 26 known Xiphophorus species, including platyfish, as a national research resource9