Are Swordtail Fish Live-Bearers?

By Nadine Oraby | 2020 Update

Are you wondering if your swordtail fish is a live bearer? Knowing your fish’s birthing process is definitely crucial for its well-being.

So, are swordtails live-bearers? Yes, this means that they give birth instead of laying eggs. Small in size, these fish are very simple to breed thus making them ideal species for beginner aquarists. Just like any live bearing fish, swordtails require no form of intervention in breeding.

This article will highlight the characteristics of swordtail fish as live-bearers and why they are famous amongst beginner aquarists.

Swordtails as live-bearers

For those who are apprentices in the field of fish keeping, swordtail fish is a perfect choice for them. A leading cause for this is that swordtails are adaptable to a wide range of water parameters and can breed quite easily.

As they come in the category of live-bearers, they do not lay eggs. Instead, they give birth to live babies known as fry. Due to their robust nature, they can breed well in varying tank conditions. Their young ones are easy to rear, and they mature quickly. A female swordtail fish can give birth to fry as frequently as every month.

Swordtail fish breeding

These live-bearers are a top priority for aquarists who are at an initial stage of learning how to breed fish. The reason behind these fish being so famous among amateur aquarists is simply because they are adaptive in nature and require no special attention from the owner.

It is recommended to maintain a 1 male:4 female ratio between your swordtail fish genders. This ratio of one male for four females helps control male fish’s aggressive behavior whilst helping the females get some break from the male counterparts.

It is also better to keep reduced number of males in the tank as increased number of male fish triggers rough behavior.

Coming to the breeding aspect of the Swordtail Fish, as discussed earlier, these fish need no sort of intervention from owners. All you need to do is place them in a tank and voila, they start breeding away!

Here is a list of some to-dos with your swordtail fish

  • Do not overstock the tank
  • Ensure that there is a lot of swimming space to foster successful breeding
  • Females should be high in number as compared to males
  • Abstain from stressing the female fish

How to Care for and Breed Swordtail LiveBearers (Video)

Identifying the female pregnant swordfish

A pregnant female shows varying signs of pregnancy and even though the gestation period of the female swordtail is 28 days, it will still be hard to gauge whether she is pregnant or not.

Keep in mind, that the gestation period of female swordfish is dependent upon different factors. They include the fluctuating water conditions, diet and the amount of stress she is going through. There are certain important pointers essential to understand your pregnant Swordtail.

Get everything ready

Once the mating is done and you see the evidence of swelling on the female swordtail fish belly, isolate the expecting mother. As her swelling becomes obvious, transfer her to a small, separate and densely planted aquarium or a false-bottomed hatching pot. There are two reasons for doing so:

  • The fry needs a separate place to mature so that when they return with the other fish in the tank, they are too large to fit in the adult’s mouth.
  • If the mother swordtail is left in the community tank after giving birth, she can become pregnant within a month. This will not only cause overcrowding in your tank, but will also stress out your female swordtails.

Appearance of a pregnant swordtail

Once you isolate pregnant swordfish, examine her growing belly daily. As the time of delivery gets close by, you will notice that her belly becomes square-shaped as if it is going to spurt.  Also, you will notice that a dark spot is emerging on each side of the body near the anus.

The pregnant female swordtail appears exhausted as she quits doing much activity in her separate pot. All she does is hang close to the tank’s bed or sink towards her gravel pot.


Swordtail fish is an excellent choice for those aquarists who are at a beginner’s stage. This freshwater fish is just like any other live-bearing fish, just a tad bit hardier.

Summarizing the swordtail fish characteristics:

  • They give birth to fry rather than laying eggs
  • They have a robust nature and can adapt to different water conditions.
  • On an average, they can deliver 30 to 35 babies at a time
  • As the swordtail fish tend to eat their own fry, it is essential to separate the young ones till they reach maturity.
  • The female swordtail fish has the tendency to become pregnant almost every month.

Swordtail fish require minimal care and maintenance in the tank. They are easy-going fish that love swimming and sometimes jumping, too. Just make sure you have a tank that fits their needs best, nothing special is needed for their breeding and well-being except some love and care.

Related questions

What is an ideal tank condition for Swordtail fish? Despite the fact that Swordtail fish are hardy in nature, they tend to thrive in certain conditions. An ideal aquarium will be of a pH level of 7.0- 8.5 with 25 gallons of water. Make sure to place a lid on top as Swordtail fish are expert jumpers and may jump out of your aquarium.

How many babies can a swordtail fish deliver at a time? Like any other species of live-bearers, a swordtail fish can deliver 10 to 60 babies at a time. On average, she can deliver 35 babies in one go. Swordtail fish multiply best when the water conditions are healthy and they are given proper nutrition.

Why does the fry need to be separated from their parents? Just like any fry of a live-bearing fish, the swordtail fish babies immediately reach maturity after four to six weeks. As the adult swordtail fish have the tendency to eat their own fry, it is best to separate them from their parents till they grow in size. There would be no purpose of breeding the swordtails if you are not willing to isolate the young ones or provide them with sufficient hiding places from the adults. Although the densely planted tanks can camouflage and hide the fry, it is still advisable to separate them to be on the safe side.


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