Do Platies and Swordtails Mate?

Yes! Platies and swordtails can mate!

It’s become pretty standard in the aquarium pet fish trade to breed two species in the hope of producing offspring with more desirable traits. Aquarists are always looking for the most compatible species for crossbreeding

The reason why there’s a wide array of bright-colored aquarium fish with such eye-catching traits is due to the inbreeding between platy fish and swordtails.

Keep reading to find out more about how to breed platies and swordtails.

Gold Platy Swimming

Do Platies and Swordtails Mate?

Yes, they do mainly because both fish species come from the same family: Xiphophorus.

They also have many similar traits, such as their origin, temperament, and feeding preferences. As a result, their fry can enjoy more prominent features, like brighter colors, longer fins, and better overall health.

Moreover, coming from the warm, lush waters of Central America, these two freshwater species require similar water parameters. So, they’re comfortable sharing the same aquarium.

In addition, they’re both low-maintenance and relatively easy to care for, which makes them ideal for beginners and inexperienced aquarists.

Creating the Right Breeding Conditions

In the wild, each fish species has an abundance of potential mates from their own kind. Yet, in captivity, it’s a whole other story.

When there aren’t enough available partners of the same species, platy fish and swordtails will do the next best thing: find the closest species.

Therefore, as long as the fish are healthy and living in ideal tank conditions, there’s no reason why these two species shouldn’t mate.

You should keep in mind four factors when breeding platies with swordtails. Check them out below.

Male to Female Ratio

The usual combination is one male platy and two or three female swordtails. This ensures that the fry shares more traits with the platy father.

Remember, there should never be more than one male, especially if you’re using a breeding tank where there’s not much space to move around. The problem is that having more than one male makes them hostile towards one another, which means the breeding won’t go very well.

Water Quality

Since both platies and swordtails are tropical fish, they require similar water parameters. Take a look:

  • Temperature: 74°F – 82°F
  • pH level: 6 – 7.5
  • Hardness: 8 – 12 dGH
  • Nitrates: shouldn’t exceed 40 ppm


In general, livebearers need more protein to sustain their health and the health of their fry. That’s why you should offer a variety of frozen and live foods.

Fish flakes are a great way to supplement their diet because they help boost the fish’s strength and maintain a healthy immune system.

Breeding Cage

The breeding cage isn’t a must, but it helps you keep an eye on the progress in general. It also comes in handy when you need to isolate the fish to ensure a successful mating process.

To set up a breeding tank, all you need is a moderate-sized tank. A 5 – 10-gallon aquarium should be enough. While you don’t need substrate, filtration is a must.

How to Determine the Gender of Platies and Swordtails

Remember, the whole purpose of breeding different species is to produce healthier, more robust offspring. In order to succeed at this, you have to know how to determine the sex of your tank fish.

Male platies have pointed anal fins, which they use for mating. On the other hand, platy females typically have more rounded anal fins. They’re also generally longer than their male counterparts.

Male swordtails have a more prominent lower fin tail, which it uses to attract the female, and is lacking in the females.

Red Swordtail. Bright orange color. Blurred dark background. Black spots.

When Are Platies and Swordtails Ready for Breeding

Both platies and swordtails are live bearers, which means the fish holds on to the eggs inside their bodies. Then, when the time is right, they give birth to live young. The cute little fries are able to swim and explore their surroundings immediately after being delivered.

You’ll know when your platy fish are ready for mating when they’re almost two months old. Their length is another giveaway; once they reach about 20mm, they’re mature enough to start breeding.

Swordtails are ready for breeding when they’re nearly three months old. By this age, they’re usually about an inch in length.

How Long is the Gestation Period for Swordtails?

The typical gestation period mainly depends on the water temperature in the breeding tank. Warm temperatures seem to speed up the process of both mating and the gestation period.

However, on average, female swordtails stay gravid for 28 to 30 days, which you can usually tell by the dark-colored gravid spot near their anal fin.

We should mention that a female can become pregnant again during a 6-month of contact with the male. The reason is they’re able to store the male’s sperm during the period, which means they can give birth once every 30 days.

Taking into account that these two species are prolific breeders that can produce about 50 fries per brood, that’s a lot of baby fish!

Fish Fry: Care Guide

Platies and swordtails aren’t known for their parental instincts. As a matter of fact, they don’t even recognize their youth as their own.

They may even go so far as mistaking them for food!

So, to ensure your fry survive the first few days of their lives, separate them immediately from the adult fish. Then, you can keep them in another tank or a breeder box for four to six weeks. Then, once they’re old enough and large enough to not fit in the mouths of adult fish, they can join the rest of the fish in your larger, more spacious aquarium.


Colorful, hardy, and easy to maintain, but do platies and swordtails mate? Yes, they do! In fact, they make one of the most ideal breeding mates when it comes to tank fish.

Still, they need the right tank and water conditions to make the process go without a hitch. You also have to be ready to protect the young fry once they arrive.

We definitely don’t want their parents snacking on them!