If you’re looking for simple, colorful additions to your freshwater aquarium, then you can go for the platyfish. Platies are small fish that come in many colours and easily adapt to life in tank environments.
These fish are excellent pets and popular scientific research subjects. Studying these fish has lead to important findings in the fields of ecology, evolution, and genetics. So, if you choose to bring these fish home, know that you’re becoming a new member of an active community of platy lovers and researchers.
What Are Platies?
Platies are part of the genus xiphophorus, which includes both platies and swordtails. Xiphophorus comes from the Greek words for “sword” and “to carry.” Fish in this genus either have long, elongated tail fins that resemble swords or regular, rounded tail fins.
One popular species, Xiphophorus maculatus, is known as the southern platyfish or the moonfish. Platyfish crossbreed with other species, so many of them are hybrids.
Unlike fish that lay eggs, platies are live-bearers, meaning that they give birth to live fish. They can easily make many babies.
Physical Characteristics of Platies
The typical platy size is quite small, which makes them suitable for a lot of aquarium setups. They grow to about 6 centimeters long but can be as small as a single centimeter in length, particularly when they’re still immature. The females tend to be slightly larger than the males, which may be 4 centimeters long.
Both sexes have stout bodies and upturned mouths. The dorsal fin (fin on the back) of a platyfish has 8-10 soft rays. These fins and their tail fins are rounded.
You can tell the difference between males and females because male platies have a pointy anal fin, like a hook, called a gonopodium, which is used to transfer sperm to the female while mating.
Natural platies are typically yellow and olive brown, and some have spots. But in aquarium settings, people have bred these fish to have a wide range of colors and hues.
Examples of aquarium platy colors include:
- Silver with black highlights
- Red with black spots
- Golden yellow with orange highlights
- Black
How long do platies live?
The exact platy lifespan depends on several factors, such as the exact species and the quality of their living environment.
In general, the better you care for your pet, the longer it’ll survive. Typically, the lifespan of a platy is about two to three years in captivity.
Platy Types
Many varieties of platyfish exist, because these fish easily crossbreed. Here are some popular varieties.
Mickey Mouse platy
This variant of the southern platy got its name from a marking at the base of its tail that looks like a silhouette of the head and ears of the animated mouse character (Mickey Mouse).
Southern platy
The southern platy, Xiphophorus maculatus, is one of the main varieties of platyfish. It’s also called the moonfish. Its colors can vary, but it’s usually olive brown with black spots or blotches.
Variable platyfish
The variable platy, also known as the variegated platy, has a more elongated body than some other types of platies. Variable platies can range in color from olive brown to silvery white to yellow-orange, and they have two or more dark, zigzag stripes on their sides. This popular species is Xiphophorus variatus.
Sunburst platy
The sunburst platy gets its name from its bright orange and yellow coloring.
Blue platy
This variety is in a bright blue shade, and it is less common than some other types.
Coral platy
The coral, or coral red, platy is in a bright coral red color, and it’s a variety of the southern platy.
Dalmatian platy
The dalmatian platy, named after its dog look-alike, is white with black spots. It’s also a variety of southern platy.
Where Do Platies Live?
Most platy species are native to Central America and Mexico. But the aquarium trade and human activity have spread them out to countries around the world. They can be found in at least 18 countries around the world, including the U.S.
Platies can live in various freshwater environments. They can even tolerate higher levels of salt contamination than other species of fish. Examples of their preferred environments include:
- Warm springs
- Canals
- Ditches
- Creeks
- Swamps
Overall, they prefer relatively slow-moving water with plenty of silt and plants for shelter and protection.
Are Platies Pests?
As platies are very common aquarium fish, people throughout the world have ended up releasing platies into non-native waterways. Platies can become pests when they’re released into non-native environments, and they are considered invasive in many areas.
Platies can be better than many native species in getting food and other limited resources. Plus, these fish have much greater reproductive success and higher survival rates in waterways that are too degraded for native fish to thrive in. Research suggests the southern platy has led to the decline of native damselflies in Hawaii.
Platies have also been found in the southern U.S.
“It’s likely that most of these invasive platies in Florida, especially, have either been released by hobbyists, or in some cases, fish farms have accidental releases, whether it'’ due to flooding or storm damage,” says Nathan Farnau, curator of fishes and invertebrates at Georgia Aquarium.
“These fish are omnivorous, and they’ll eat pretty much anything, and that includes insect larvae,” Farnau says. “So they can really fundamentally alter an ecosystem by decimating native insects and even some aquatic plants as well.”
Platyfish Care
You can keep these fish in an aquarium all by themselves or mixed in with other species of fish. Just make sure that you have a good balance of male and female platies. If you have too many males, they may fight one another.
What do platies eat?
Platies are omnivores. They can feed on most of the plants and animals around them. This includes:
- Worms
- Crustaceans
- Insects
- Plant matter
In an aquarium setup, you can feed them commercial fish pellets or flakes. Consult your local pet store for brand recommendations.
Ideal tank setup for platies
Platies can adapt to a wide variety of aquarium settings, but they do best in conditions that mimic their native environment. This includes:
- A water pH of 7-8
- A water dH (measures water hardness) of 9-19
- An ideal platy temperature range of approximately 65 F to 77 F
- Plenty of light
- Plenty of plant life — real or fake — to hide in
- Aquarium gravel or sand
A 10- to 20-gallon aquarium is a good size for platies. Also, make sure that your aquarium has a tight-fitting lid. Platies may jump right out of the tank.
Common Health Issues in Platies
Typically, platies are not prone to disease if you maintain good water quality, Farnau says.
But, like all pets, your platies can develop health issues throughout their lives. Common problems in aquaculture communities include infections from viruses and parasites.
Platyfish diseases
Platies may be affected by an infection called oomycete or by a parasite called ichthyophthiriosis, or ich. They can also get a number of common fish diseases such as fin rot and velvet.
Many fish diseases are fatal, and it’s difficult to find a veterinarian who specializes in aquarium pets. Although fish medicine is a growing field, most vets are trained to work in large-scale aquaculture settings and not with individuals.
You can try consulting employees at your local pet stores for advice on a health issue in your pet, but there’s no guarantee that you’ll find an expert on your particular problem.
Overall, platies tend to be a healthy, sustainable breed that does well in most freshwater aquariums. Just make sure that you’ve got the right equipment and care information before you bring these fish home.
For most live-bearing fish like platies, it’s good to maintain a low level of hypersalinity, as it helps them fight parasites, Farnau says. To do this, you can keep a little bit of salt in their water, usually between one and three parts per thousand, he says.
Breeding and Reproduction of Platies
The male platy’s anal fin is used to transfer sperm to the female for mating.
Many species of fish lay eggs, but female platies give birth to live young. They give birth to 20-50 individuals at one time. The young reach sexual maturity after three to four months and start reproducing on their own.
The fish breed very easily, so they’ll likely start having young in any setting where you’ve gathered males and females together, even in modestly sized aquarium setups.
“They are very reproductive and successful in aquariums, having babies; so you get six, and you end up with 50, and you don't know what to do with them,” Farnau says.
If you end up with more platies than you want, make sure you don’t release them into waterways.
“Releasing non-native fishes into waterways locally is a very, very destructive practice, and it may be counterintuitive for some folks, because they think that they’re setting their fish free or giving them a better home, when in fact, they’re damaging an ecosystem,” Farnau says. “There’s an ecological responsibility in finding alternatives to releasing these animals if they’re no longer wanted in a personal collection.”
Pregnant platyfish
When platyfish are pregnant, it’s obvious, Farnau says. Much like pregnant humans, pregnant platies get round bellies, and “they get especially fat prior to releasing the babies,” he says.
Because platies reproduce easily, a female platy may spend a big amount of time pregnant and having babies.
Takeaways
Platies are popular fish to keep in an aquarium, and they come in many colors. They tend to get along well with other fish and are fairly easy to keep. They reproduce easily, though. So, if you start keeping platies, you should be aware that you might end up with more of them than you want. If this happens, it’s important not to release unwanted platies in bodies of water, as they are invasive and can damage the ecosystem.
Platies FAQs
What size aquarium should I get for platies?
Platies do well in an aquarium that’s at least 10-20 gallons big.
What are good platyfish tank mates?
Platies generally do well with other fish, and tetras and cory catfish may be good tank mates.
How active are platyfish?
Platyfish are active and curious.
Where can you buy platies?
You can buy platies at pet stores and from online aquarium sites.
What is the medicine for fish diseases?
The medicine you need to treat a fish disease depends on the particular fish and disease, but there are products you can buy at pet and aquarium stores to treat diseases.
How to treat parasites in platyfish?
The treatment for a parasite in platyfish will depend on what the parasite is, but you may need to use medication and change the water in the tank.
