The Platy is considered the color king of the live-bearingfishes!

The brightly colored Platy fish have remained very popular among aquarists for good reason. Although they are rarely found in purple, Platies come in almost every color of the rainbow as well as black and white. They are very peaceful, which makes them great community fish, but they will happily live with their own kind as well. The aquarist can keep a complete rainbow of coloration housing just this one type of fish!

Platies are members of the Xiphophorus genus. Three species are commonly available to the hobbyist. These are the Southern Platy Xiphophorus maculatus, also known as Common Platy or Moonfish, the Variatus Platy or Variable Platyfish Xiphophorus variatus, and their close relative the Swordtail Xiphophorus helleri. A rare to obtain but also stunning species is the Swordtail Platy Xiphophorus xiphidium, which features a small extension on the tail.

The Southern and Variatus Platies are both short, stocky fish, though the Variatus is slimmer and more elongated. Both varieties also lack the extended tail fin or “sword” of the Swordtail. Common types of Southern Platy are the Comet, Two-spot, Halfmoon, Moon, Salt and Pepper or Pepper and Salt, Coral, Blue Mirror, Bleeding Heart, and of course the popular Mickey Mouse Platy. Common types of Variatus Platies are the Sunset Platy, Marigold Platy, and Hawaii Platy.

These species have been intensely hybridized with each other as well as the Swordtail, making a true bred fish rare. It is now even hard to distinguish among the species. Color and fin shapes vary wildly, but in general if the male has a sword-shaped tail, they are called Swordtails and are otherwise labeled Platy. This interbreeding has produced a plethora of exciting variations. Today, Platies come in just about all colors and mixtures of colors. The many beautiful variations give the aquarist a wide selection!

The Platy is one of the best beginner fish and an excellent addition to a community. They are active, very hardy, and will breed readily in the home aquarium. The males in particular stay small, so they are suitable for even small aquariums. This fish is available just about everywhere at a very reasonable price.

The Platy is not finicky about conditions. As long as the aquarium water is clean and within their water chemistry and temperature tolerance, the Platy will rarely have issues. Some planting of the aquarium is appreciated as it mimics this species’ natural habitat.

For Information on keeping freshwater fish, see:
Freshwater Aquarium Guide: Aquarium Setup and Care

Platy fish

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Platies pretty and hardy, a great fish for anyone!

Platies are beautiful and fun to keep, here’s a quick look at selecting, caring and breeding them.

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Cyprinodontiformes
  • Family: Poeciliidae
  • Genus: Xiphophorous
  • Species: maculatus
Platies – Moonfish – Quick Aquarium Care
  • Aquarist Experience Level: Beginner
  • Size of fish – inches: 2.8 inches (6.99 cm)
  • Minimum Tank Size: 10 gal (38 L)
  • Temperament: Peaceful
  • Aquarium Hardiness: Very Hardy
  • Temperature: 70.0 to 77.0° F (21.1 to 25.0&deg C)
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Habitat: Distribution / Background

Platies are members of the Xiphophorus genus. There are about 28 species in this genus, and all are called either Platy fish (or Platies) or Swordtails. The Southern Platy Xiphophorus maculatus was described by Günther in 1866. The Variable Platyfish Xiphophorus variatus was described by Meek in 1904, and their close relative the Swordtail Platy Xiphophorus xiphidium was described by Gordon in 1932.

These three species are collectively known as Platy today. They are members of the Poeciliidae family, all of which can hybridize with one another. All three species are indigenous to Central America. The Southern Platy X. maculatus is native to the Atlantic coast of Mexico and Guatamala, as well as northern Honduras. The Variable Platyfish X. variatus are found in southern Mexico from Rio Panuco to Rio Cazones. The very rare Swordtail Platy X. xiphidium inhabits exclusively the Rio Soto La Marina river system in Mexico. These fish are not endangered nor are they listed on the IUCN Red list of Threatened Species.

The Common or Southern Platy is, as the name suggests, the most common variety of Platy. It was first introduced to aquarists in 1907 when they were often called “Moonfish” because of a crescent-shaped dark spot at the base of the tail, especially on the yellow ones. This fish is credited as one of the species that sparked increased interest in aquarium-keeping due to its charms and easy care. Other common names this species is known by are Common Platy and Moonfish. Popular, selectively-bred ornamental varieties include the Comet Platy, Two-spot Platy, Half-moon Platy, Moon Platy, Salt-and Pepper or Pepper-and-Salt Platy, Blue Mirror Platy, Coral Platy, Bleeding-heart Platy, and Mickey Mouse Platy.

The Variable Platy was aptly named due to its great deal of natural color diversity. Other common names this species is known by are Variatus Platy, Variable Platyfish, and Variegated Platy. It was identified in 1904 but not introduced into the hobby until 1932 when they were an immediate hit and become one of the best-liked livebearers. Popular, selectively-bred ornamental varieties include the the Sunset Platy, Marigold Platy, and Hawaii Platy.

The Swordtail Platy, which remains relatively unknown, was described much later than the other two by Gordon in 1932. It is a very sensitive species in which the male has a short, sword-shaped tail. This delicate platy is rather rare. It is also known as the Spike Tail Platy.

Since their introduction, Platy fish have risen in popularity and been bred to produce multifold strains with different fin shapes and color patterns. Cross-breeding with the Swordtail has produced great diversity in fin shapes, including Sailfin, Topsail, Brushtail, and Plumtails, to name a few. Popular color varieties include the Wagtail, Rainbow, Salt and Pepper or Pepper and Salt Platy, Tuxedo, and Mickey Mouse Platy.

In the wild, all three species inhabit canals, ditches, warm springs and marshes. The Swordtail Platy seems to have the strongest aversion to rapid water flow, while the Southern Platy is more tolerant of a small current. They prefer warm, small bodies of water with silt bottoms and dense vegetation. Though not a schooling fish, they do enjoy the company of other Xiphophorus, so will often shoal in groups. They feed on plant matter, worms, crustaceans, and insects.

  • Scientific Name: Xiphophorous maculatus
  • Social Grouping: Groups – Platies are not a schooling fish, but they enjoy being with other Xiphophorus.
  • IUCN Red List: NE – Not Evaluated or not listed


Platies are laterally compressed fish, stocky with relatively compact fins and a fan-shaped tail, with the exception of varieties bred for larger fins. The Southern and Variatus Platies are both short, stocky fish, though the Variegated is the slimmer and more elongated of the two. Both also lack the extended tail fin or “sword” of the Swordtail. A rare to obtain but also stunning species is the Swordtail Platy Xiphophorus xiphidium, which features a small extension on the tail.

Blue Hifin Variatus Platy, Xiphophorous variatus
Blue Hifin Variatus Platy Photo Courtesy Ken Childs

Along with Mollies, Guppies, and Swordfish, the Platy is a member of the Poeciliidae family of live-bearing Toothcarps, which are distinguished by having teeth in both their upper and lower jaws.

The Southern Platy females get up to 2.5 inches (7 cm) in length, while the males are somewhat smaller at 2.0 inches (6 cm). The Variegated Platy females can get up to 3 inches (9 cm) with males, again, somewhat smaller. The size of these fish varies a lot depending upon sex and variety.

Overall, males of each species will seldom exceed 1.5 inches (4 cm) in length (although Variable Platys occasionally exceed this). The female is notably larger in all species, reaching easily up to 2.75 inches (7 cm). As the male fish matures, the middle rays of its anal fin modify into a narrow copulatory organ with a strong hook called a gonopodium.

The Southern and Variatus Platys have been cross-bred with the much rarer Swordtail to produce a variety of finnage, including Topsails, Sailfins, Hifins, and Plumetails or Brushtails.

Blue Mickey Mouse Platy, Xiphophorous maculatus
Blue Mickey Mouse Platy Photo Courtesy Newman

The coloration of Platies is highly variable. Most are based in the red and yellow part of the spectrum, with other varieties bearing black, white, greenish and even blue coloration. So many beautiful color variations and hybrids have been produced, it is difficult to find pure-bred original strains. Today, pure breds are the exception rather than the rule.

The wild colorations for pure-bred Platy species are many and varied but depend upon the river systems from which they originate. They each also have a bit different color scope.

The Variatus Platy has just one ground color, known as the wild-color, which is gray or olive-green, while the Southern or Common Platy has three: wild-color, albino, and blond. The cover colors of the Common Platy are red, blue, marigold (a yellowish orange), and black. Cover colors on the Variable Platy are blue, gold, marigold, and black.

Popular “true-bred” types of Southern Platy are the Comet Platy, Half-moon Platy, Moon Platy, Salt and Pepper or Pepper and Salt Platy, Coral Platy, Blue Mirror Platy, and Bleeding Heart Platy. There is also the Two-Spot Platy, which has two small dots at the top and bottom where the tailfin begins and the similar Mickey Mouse Platythat sports two small dots with a large, dark spot in the middle.

Gold Wag Platy, Xiphophorous hybrid
Gold Wag Platy Photo Courtesy David Brough

Popular varieties developed from the Southern or Common Platy:

  • Solid colored fish
    The solid colored fish include the very popular Red Platy or Coral Platy, which is either a deep blood red or a brick red, and the Golden Platy, which is a bright yellow color. .
  • Moonfish
    The term “Moonfish” applies to fish of a specific color and a distinctive, black crescent-shaped dot on the tail fin. These include the Red Moon Platy, Blue Moon Platy or Blue Platy, and the Gold Moon Platy or Gold Crescent Platy.
  • Wagtail
    The term “Wagtail” applies to fish of a specific color with deep black tails. These include the Red Wagtail Platy, Gold Wagtail Platy, Black Wagtail Platy, and the Mixed Wagtail Platy.
  • Tuxedo
    The term “Tuxedo” applies to fish of a specific color with a black coloration below the lateral line from the gill to the tail. These include the Black Platy, often called the Black Tuxedo Platy, or Green Tuxedo Platy, which has a greenish body.
  • Salt-and-Pepper Platy (or Pepper and Salt Platy)
    The Salt-and-Pepper Platy is mixed with a bit of all the colors, and it breeds these colors true. This is the same fish as the Hybrid Swordtail. If they retain the “sword,” they are called Hybrid Swordtail rather than Salt-and-Pepper Platy. No two fish are alike but all contain bits of black, red, yellow, and green blotches.
  • Mixed Platy
    The Mixed Platy has various various colors, just like the Salt-and-Pepper Platy, but with no particular pattern, and it doesn’t breed true.

Popular varieties developed from the Variable Platyfish or Variatus Platy:

  • Redtail Platy – varieties have a tail that is bright red.
  • Yellowtail Platy – varieties have a yellow tail fin.
  • Sunset Platy – varieties have a tail containing many colors but with yellow usually being prominent; they also may have a yellow dorsal fin and a red tail fin.
  • Rainbow Platy – varieties have a tail with multiple colors in which no one color is prominent.
  • Hawaii Platy – have an entirely black body with a yellow dorsal fin and red tail fin.
  • Marigold Platy – have yellow on the dorsal fin and top of the body with the lower half and the tail fin being orange.

Male Platies won’t show their colors until they are mature, and they will show best if the aquarium is kept at the cooler end of their temperature range. They can be expected to live around 3 years, though they can live 5 years or more with optimal care.

  • Size of fish – inches: 2.8 inches (6.99 cm) – Females are larger, while the males usually only reach about 1.5 inches (4 cm) in length.
  • Lifespan: 3 years – On average, these fish will live about 3 years, but if well cared for, they can live up to 5 years or even longer.

Fish Keeping Difficulty

The Platy fish is an active swimmer, but peaceful, making it suitable for community tanks. It is easy to care for and to breed, making it an excellent beginner fish. The Swordtail Platy, uncommon in the aquarium hobby, is the one species that is less tolerant of the varying conditions of a home aquarium. Make sure you select only healthy fish and provide a good tank and varied diet to offset any potential problems.

The widely available varieties of these brightly colored fish can be kept in a smaller tank than the Swordtail and are more peaceful, active, and hardy. They are also dependably prolific. An aquarium best suited to the platies is well-lit and contains plants. Some floating plants are recommened to let the fry to hide. Though Platies do not eat their fry, other community tankmates will. Like all livebearers, they do like a bit of salt, though it is not necessary. This fish can jump, so be sure to provide a secure cover for the aquarium.

  • Aquarium Hardiness: Very Hardy
  • Aquarist Experience Level: Beginner

Foods and Feeding

These fish are considered omnivorous, but the Platies have a very high herbivorous requirement, and their diet needs to include lots of algae and other vegetation. In the wild, their diet consists of worms, crustaceans, insects, and some plant matter. In the aquarium, they will gladly eat most commercially-prepared fish foods as well as supplementary live and vegetable-based food. Feed brine shrimp (either live or frozen), tubifex, or blood worms as a treat. They will enjoy the proteins, but they must also have plenty of vegetation in their diet.

The Platy seems to have little preference in what it eats, although a good, varied diet is essential to the health and long life of most aquarium fish, including this one. A vitamin-rich diet encourages the best coloration. Platies will occasionally consume algae within the aquarium. This fish is not a picky eater but should be fed a varied diet several times daily in small amounts.

  • Diet Type: Omnivore – This fish is an omnivore; however, it appreciates a high vegetable component in its diet.
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet
  • Vegetable Food: Some of Diet
  • Meaty Food: Some of Diet
  • Feeding Frequency: Several feedings per day – Feed small amounts several times a day–what the fish can consume in about 3 minutes each time.

Aquarium Care

The Platy is usually without health problems and undemanding as long as the pH of the aquarium does not sink too low. Water changes should be kept regular to ensure that decomposing waste does not cause pH changes or introduce too many toxins into the water. The tank should have regular water changes of 25% every 2 -4 weeks. It will need more or less depending how many fish there are and the condition of the water. Good water conditions are especially important for the Swordtail Platy, as it will quickly deteriorate in a poor environment.

It is also advisable, as with most of this family, to add 1-1.25 teaspoons of aquarium salt per gallon. Remember to only replace water with salted water if one has removed water from the tank. Evaporating water leaves salts behind, so there is no need to add more salt if one is topping off evaporated water.

  • Water Changes: Monthly – Do water changes of 25% every 2-4 weeks or more frequently with heavily-stocked tanks.

Aquarium Setup

Platies are small, active fish, and a 10 gallon tank is the suggested minimum size. Although this is not a shoaling fish, it enjoys being kept in a group with a few of its own kind. A ten gallon tank (38 Liters) would suffice for a group of up to 5 individuals; however, the aquarist should keep in mind that if fish of both sexes are included the tank, population will rapidly increase due to the frequent breeding of these fish and quick maturation of the young. A one-to-three ratio of males to females is preferable to reduce quarrels among the males over potential mates.

They are tolerant of water conditions, but good filtration is very helpful in maintaining stable water. Filtration systems remove much of the detritus, excess foods, and waste. This in turn helps to keep the tank clean and maintain the general health of the fish. Good water conditions are especially important for the Swordtail Platy, as it will quickly deteriorate in a poor environment.

Most any type of gravel works fine for a substrate, but the Platy appreciates a planted tank to mimic its natural habitat. Plants should be loosely arranged for the Southern Platy, and densely planted with open swimming areas for the Variatus Platy. Floating plants are a good idea if the aquarist wishes the offspring to survive.

The Platy shows its colors best at maturity in a slightly cooler tank. As with most livebearers from this region, a small amount of aquarium salt in the water, 1-1.25 teaspoons of aquarium salt per gallon, is appreciated. Be sure the tank is covered as they can jump.

  • Minimum Tank Size: 10 gal (38 L) – A 10 gallon tank can house a group of up to 5 individuals; however, they are very prolific. The tank population will rapidly increase due to their frequent breeding.
  • Suitable for Nano Tank: Yes
  • Substrate Type: Any
  • Lighting Needs: Moderate – normal lighting – This fish does not have strong lighting preferences.
  • Temperature: 70.0 to 77.0° F (21.1 to 25.0&deg C) – The temperature should be between 70-77 °F (21-25°C) for the Common and Swordtail Platy, while the Variable Platy prefers 72-75°F (22-24°C).
  • Range ph: 6.8-8.0
  • Hardness Range: 10 – 28 dGH
  • Brackish: No – This is not a brackish water fish, but it does appreciate a little salt. Use about 1-1.25 teaspoon per gallon of water.
  • Water Movement: Weak
  • Water Region: All – These fish will swim in all areas of the aquarium but mostly in the middle and top.

Social Behaviors

The Platy is an excellent community fish that is very peaceful but active. It does not look for trouble with other tankmates and enjoys swimming in loosely grouped schools. The males will occasionally squabble amongst themselves but generally without any damage done.

This fish can be housed with fish of similar temperament and size that have the same water chemistry requirements. Many aquarists choose to keep it with its relatives, the Molly and Guppy, in a geographically-themed tank. This friendly fish combines well with all good-natured small fishes. Armored catfish (Corydoras), Platy fish, Tetras and other Characins make good tankmates.

  • Venomous: No
  • Temperament: Peaceful
  • Compatible with:
    • Same species – conspecifics: Yes
    • Peaceful fish (): Safe
    • Semi-Aggressive (): Threat
    • Aggressive (): Threat
    • Large Semi-Aggressive (): Threat
    • Large Aggressive, Predatory (): Threat
    • Safe
    • Shrimps, Crabs, Snails: Safe – not aggressive
    • Plants: Safe

Sex: Sexual differences

The female is larger when fully grown and generally rather plain, though in many of the fancy Platies today, they have more color. It is difficult to sex Platies until they are mature as the male does not attain his coloration until then. As they mature, the males develop a modification of the anal fin into a rod shape, called a gonopodium, which is used in the reproductive process.

Breeding / Reproduction

This live-bearing fish breeds readily in the home aquarium without special attention if well fed and cared for. In fact, the young reach sexual maturity at four months of age and can quickly overpopulate an aquarium. For breeding Platies, little more is required than to introduce both sexes into the aquarium.

To selectively breed Platy fish, provide a breeding tank that is 10 to 20 gallons in size with gentle filtration. You will notice a female is pregnant when she develops a gravid spot, a dark mark on her abdomen. The gestation period is about 24 to 30 days.

In a community aquarium, the young will be consumed by other tankmates unless they are removed, isolated (as with a breeding trap for example), or simply given enough hiding spaces with densely rooted or floating plants. The female Platy can have between 20 and 80 fry, but will generally produce 20-40 young at a time. For more information, see the guide for breeding Livebearing Fish: Breeding Freshwater Fish – Livebearers.

  • Ease of Breeding: Easy

Fish Diseases

Platies are generally quite hardy and do not have any particular weaknesses for certain diseases. However, it can still fall victim to the common ailments of aquarium fish, such as Fin Rot and Ich. Platies are subject to the same diseases as other tropical fish. The best way to proactively prevent disease is to give them the proper environment and a well-balanced diet. The more closely the aquarium mimics their natural habitat, the less stress the fish will have, making them healthier and happier. A stressed fish is more likely to acquire disease.

Anything you add to your tank can introduce disease. Not only other fish, but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so as not to upset the balance. For information about fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


The Southern Platy and the Variable Platy, as well as their hybrids, are some of the most commonly available aquarium fish and are usually modest in price. The Swordtail Platy is very difficult to come by.