Poeciliidae – Swordtails & Platies (Xiphophorus)

Updated on January 30, 2021 by

Hardy and colourful fish, Xiphos make a wonderful addition to the common aquarium. Easy to breed, they will display great colour varieties. Without asking much in return, Platies bring a lot of interest to any aquarium, especially if kept in groups.

Their energetic swimming only draws attention to their pretty scales and delicate form​.

Quick stats – Swordtails and Platies

Category Info
Origin Central America
Max size 3” / 9 cm
Aquarium Min 10 gallon / 35
Water 70-77° F / 21-25° C

KH 10-30, pH 6.5-8.0
Care level Easy
Behaviour Peaceful
Diet Omnivore
Family Poeciliidae
Colors Red, blue, yellow, gold

Swordtails and Platies description

Platies are freshwater fish belonging to the Poeciliidae family and members of the Xiphophorus genus. They are native to the canals, ditches, warm springs and marshes of Central America stretching from Mexico, Veracruz to northern Belize. In the wild, they prefer warm water bodies with silt substrates and dense vegetation.

Generally, they are laterally compressed fish, stocky and possess compact fins, a fan-shaped tail and 2 rows of jaw teeth.

They exhibit sexual dimorphism with the female being larger than the male, with the female growing up to 3’’ (9cm) while the male would grow up to 2’’ (6cm). As the male matures they develop a gonopodium which is a narrow copulatory organ with a strong hook which results from the modification of the middle rays possessed by the anal fin.

These popular Platies fish have been specially cross bred to produce subspecies possessing different fin shapes and coloration.

The Platies are made up of three different varieties with peculiar personalities, distinctive body types and coloration, which includes the Common or Southern Platy (Xiphophorus maculatus), the Variable Platy (Xiphophorus variatus) and the rare but popular Swordtail Platy (Xiphophorus xiphidium).

Common or Southern Platy (Xiphophorus maculatus)

Xiphophorus maculatus

Just as the name implies, these are the most common variety of the Platy fish. They are also called moonfish, owing the name to the crescent-shaped dark spot at the base of the tail. They are short and stocky.

The male possesses a pointed caudal fin. As the male matures they develop a gonopodium which is a narrow copulatory organs with a strong hook used for reproduction which results from the modification of the anal fin.

The female possesses a fan-shaped anal fin. They are not brightly colored like the males and also lack the distinctive lateral lines that are common to many Xiphophorus species.

They have several subspecies that have been selectively bred which come in varying colors, but mainly occurring in blue coloration usually with a yellow or red fin. Popular selective breeds of the common platy includes, Half-moon Platy, Moon Platy, Two-spot Platy, Salt-and-pepper Platy, Mickey Mouse Platy, Blue Mirror Platy, and Bleeding-heart Platy.

Variable Platy (Xiphophorus variatus)

Xiphophorus variatus

Otherwise called the Variatus Platyfish or Variegated Platy, the Variable Platy owes its name to the great diversity in their natural coloration and body patterns. They are known to have a ground color known as the wild-color with variable cover colors including black, marigold and blue.

They possess 20-24 lateral scales and 10-12 dorsal fins. They also have the ability to thrive in a more cold region than other fish.

The mature males have blackish blotches on their dorsal fin. The males have a more pointed/needle-like anal fins, while the female have a more triangular anal fin.

They have several subspecies that have been selectively bred and come in varying colors, but mainly occurring in blue coloration usually with a yellow or red fin. Popular selective breeds of the Variable Platy includes, Hawaii Platy, Sunset Platy, Redtail Platy, Yellowtail Platy, Marigold Platy and Rainbow Platy.

Swordtail Platy (Xiphophorus helleri)

Xiphophorus helleri

Swordtail Platy is not seen so often as the others, but it’s nevertheless a stunning variety of the Platy fish. They possess a ‘’sword’’ on their caudal/tail fin which gives them their name ‘’Swordtail Platy’’.

The male Swordtail Platies are smaller and slimmer than the female with a more distinctive swordtail. The male grows to 5.5’’ (14cm) while the female grows larger to about 6.6’’ (16cm).

The Swordtail Platy has many varieties including the Montezuma (Spotted) swordtail, Delicate Swordtail, Mountain swordtail, and the popular Green or Red Swordfish.

The Green Swordfish naturally has an olive green body with red, yellow or brownish stripes along the lateral line of the sides.

The Swordtail Platy has been selectively cross-bred with other Platy varieties including the common and variable Platy to produce varieties of cross with distinctive and exaggerated fin shapes including Wagtails, Sailfins, Brushtails, Topsails, Hifins, among many others. Some cross even possess two sword fins.

Swordtails and Platies in the natural habitat

They originate from the canals, ditches, warm springs and marshes of Central America stretching from Mexico, Veracruz to northern Belize.  They prefer small and warm water bodies with silt substrates. 

As peaceful species, they prefer areas with dense vegetation to provide them with shades and hiding places. In the wild, they feed on plant matters, worms, crustaceans and insects.

Swordtails and Platies in the ideal aquarium

Platy fish are small but active swimmers. Setting up the ideal aquarium for Platies will require a well filtered 10 gallon tank to house 4-5 Platies, preferably in the ratio of 1 to 3 male to female. The tank should be fitted with a lid, as these active swimmers tend to jump.

The water movement should be weak and have a pH range between 6.5 and 8.0, hardness of 10-28 dGH and temperature of 21.1 – 25.0˚C (70 – 77F). However, the Swordtail Platy prefers a temperature range of 21-25˚C, while the Variable and Southern Platy will prefer a temperature range of 22-24˚C. So striking a temperature balance between the two will be suitable to house the three different varieties.

They can tolerate varying water conditions, but if a Swordtail should be kept in the tank, then adequate water conditions should be maintained, as the Swordfish are not adaptive to water poor conditions and are susceptible to diseases. The water should be changed every two weeks, replacing up to 50% of the water.

As with many livebearers, they would appreciate a small quantity of aquarium salt in their tank. About 1 teaspoon per gallon would be great. Nonetheless, keep in mind that they’re not a brackish water fish.

As active swimmers which often occupy the middle and upper region of the tank, they can thrive in any substrate, but a silt substrate will be great. 

As peaceful species, all Platies prefer a tank with dense vegetation to shade and give them hiding spots, but this should not be overcrowded as these active swimmers will still need enough swimming space to explore their tank. Floating plants and driftwoods can be used to add decoration to the tank. They will also help to diffuse the light that enters the tank.

These species do not prefer heavy lighting, so a normal moderate lighting would be comfortable.

Although they are not social fish, they are excellent community fish and are best kept with fellow Platy fish. The males might squabble with each other but without causing any visible damage to each other. 

They can also be housed with other species with the same peaceful temperament that are also adaptive to their water chemistry.

Suitable tankmates of the Platy includes; Mollies, Guppies, Corydoras, Tetras and Characins. They are also compatible with invertebrates including Shrimps and Snails.

As peaceful species, they are unsuitable tankmates with aggressive species, as they would harass and inconvenience the Platies. Also fin nippers such as the Tiger Barbs should be greatly avoided as they would nip on the fins of the Platies. Larger carnivore species should also be avoided as they would prey on these peaceful Platies.

Swordtails and Platies feeding

As omnivores, Platies will feed on meaty foods and vegetables, but they tend to be highly herbivorous and have a craving appetite for vegetables. In the wild, they will feed on aquatic invertebrates, algae and other plant matters.

They are unfussy eaters and will eat almost anything they are fed, but their diet should be balanced with good quality foods which are vital to their health. Daphnia, Artemia, and Bloodworm are yummy meaty food for the platies.

Their diet should contain a high vegetable content, and vegetables such as cucumber and spinach will meet their veggie needs. Their meal can be supplemented with high quality and nutrient enriched processed foods, flakes and pellets.

They should be fed several times a day with just a little amount they can finish in 3 minutes. Any leftover should be removed as soon as they are done eating to improve the tank hygiene.

Swordtails and Platies breeding

Breeding Platies is very easy. If well fed and cared for, they can readily breed in their aquarium without any special attention. 

However, to improve breeding and for selective cross breeding, a different 10 gallon breeding tank could be set up. The water condition should be the same with the main tank. 

A breeding pair can be introduced. They will easily pair up and breeding will take place. A dark mark (gravid spot) on the abdomen of the female platy indicates she is pregnant. They will through a 24-30 days gestation period.

The female Platy will usually produce 20-40 fry at a time, although they can also produce up to 80 fry.

The Swordtail Platies have a great tendency of eating their fry, so the parents should be separated as soon as the fry are out.

The fry can be fed with smaller live food like the baby brine shrimp and crushed vegetables until they are mature enough to eat heavier foods.

To conclude

Platies are hardy and peaceful fish belonging to the Poeciliidae family. They are divided into three main varieties each with peculiar attributes and personalities. They include the Common or Southern Platy (Xiphophorus maculatus), the Variable Platy (Xiphophorus variatus) and the rare but popular Swordtail Platy (Xiphophorus helleri).

They have been selectively cross-bred with each other to produce varieties with distinctive body patterns and coloration.

They can thrive in varying water conditions, but care must be taken to maintain the tank condition if the Swordfish platy would be introduced as they are susceptible to varying water conditions and prone to certain diseases.

They are omnivores, but have a high herbivorous tendency with a craving appetite for vegetables.

Breeding Platies is very easy, as they are livebearers and can even breed in the aquarium tank without any special attention. With proper care and right tank condition, Platies can live up to 5 years.

Swordtails and Platies FAQs

What is the maximum size of Platies fish?

Platies can grow to a maximum size of 3’’ (9cm) on average.

What are suitable tankmates for Platies?

Suitable tankmates of the Platy includes; Molly, Guppy, Corydoras (Armored Catfish), Tetras and characins. They are also compatible with invertebrates including Shrimps and Snails.

What are the food requirements of Platies?

They are generally omnivores, but have a craving appetite for veggies. Cucumber and Spinach will meet their veggies need, while Daphnia, Artemia, and Bloodworm are yummy meaty food for the Platies.

For how long do Platies fish live?

With proper care and adequate tank condition, Platies can live up to 5 years.