I had a pregnant swordtail fish that was very close to giving birth. I thought I’d move her to a brooding tank tomorrow day. When I went to the tank in the morning, tiny fry was swimming all over the place. That made me wonder if swordtails give birth at night.
Swordtail fish are a type of live-bearing fish, which means they give live births. I did some research to find out that livebearer fish like mollies, guppies, platies, swordtails, etc. do usually give birth at night, in the dark.
However, there are also cases when these fish have given birth during the day. So, it means all the livebearers including swordtails give birth whenever they are ready, but most of the time at night.
In this article, we will talk about a few of the breeding-birthing habits of swordtail fish.
Do Swordtails Give Birth At Night?
A swordtail is a type of livebearing fish that gives birth at night. Swordtails are typically nocturnal, which means they give birth to their babies in the dark.
Although this may be inconvenient for humans who want to watch them, it’s actually better for the baby fry because they’re less visible and therefore have a greater chance of survival.
Usually, a pregnant swordtail fish gives birth at night in a dark environment to protect her fry from predators or aquarium inhabitants. But there are reports that some females can give birth during the day if they feel safe enough by hiding among plants or rocks. Not only swordtails, but almost all livebearers also tend to give birth at night most of the time.
Thus, to make sure your swordtail will give birth at ease when you are not there, you should shift her to the brooding tank when the gestation period is close to an end.
Why Do Swordtails Give Birth At Night?
Swordtail fish give birth at night in order to avoid predators. They do this while hidden underneath rocks or plants where there is little light so that they can keep their fry safe from harm and continue the swordtail lineage without interruption.
Pregnant female swordtails lead a solitary lifestyle during pregnancy for the protection of their young until they are ready to give birth. They spend their time hiding under rocks and plants during the day, venturing out only at night when it is safer for them and their fry.
It is better for them to be less visible when giving birth, so it will take place under darkness and inside the protection of plants.
I know we’ve talked about swordtails eating their own babies, but a pregnant swordtail still wants to deliver her babies safely, into a safe environment. It’s the labor and fatigue that tempts her to eat the fry at the end.
How To Set The Birthing Environment For Your Swordtail?
Now that we know the birthing usually takes place at night, in the dark, you could set up a similar environment for your swordtail fish.
If you have tank lighting, you can dim it down a little bit, even during the day, to make it dark around the tank. This could induce birthing. If you shift your pregnant swordtail to a safe place and simulate darkness, she might feel safe enough to drop her babies.
Other than that, you could cover the tank with dark clothes or use a night-time setting on your computer. You can also try to simulate darkness by using red lights, as some believe that swordtail fish give birth in this kind of condition.
How Do Swordtails Give Birth?
After the mating, swordtail female starts to develop zygotes inside their belly. Then, the zygotes slowly develop into tiny little fry and you can see this through the dark gravid spot that develops near the anal fin of the female swordtail. This is how you know that your swordtail female is pregnant.
After about 28 days, the swordtail female is ready to give birth. How will you know? She will limit her movements and will hide among the plants. This should be the right cue for you to shift her into a separate tank, if not already.
The labor can take a few hours. Swordtails give birth to almost 150 fry at one time. Some swordtails like to take a rest in between birthing, maybe because she is tired.
Then comes the cute little fry that will immediately start swimming all over the tank.
Can Swordtails Give Birth Over A Few Days?
Swordtails can give birth over a few days or all at once. It’s rare to see them giving birth all at one time, but it does happen! If you’re worried about your Swordtail being pregnant and have seen her struggling for labor, chances are she will take a break to birth all the live fry.
Swordtails can give birth over 48 hour period, doesn’t have to be at night all the time.
It is important to set up a proper environment for the parents and babies so they feel safe and secure.
You’ll need a small tank (no more than 20 gallons) with plenty of plants, rocks, or wood; some live plants are ideal because they provide food and shelter as well as oxygen – either a filter or air pump to keep the tank clean and provide oxygen; a heater (if it is winter).
Since, we know now that livebearers usually give birth at night, in the dark, it is better to turn off the aquarium light at night.
Signs That Your Swordtail Is Ready To Give Birth
swordtails usually give birth at night to protect their fry. But there are cases where they have given birth during the day. This means, swordtails really give birth whenever they are ready and feel safe.
You should be careful to notice all probable signs that your swordtail is ready to give birth. The signs include:
- the gravid spot on her belly will be bigger
- she’ll become less active and spend more time beneath rocks or plants
- she may seem restless, rubbing against objects in the tank, acting like this is not a safe place to give birth.
The female swordtail can have up to 150 fry at one time! They come out tiny and without any scales, but at birth, they are called livebearers because they can swim immediately.
FAQs
How Long Does It Take For Swordtails To Give Birth?
Swordtails are pregnant for about 28 days. This is the time when the egg fertilizes inside the female swordtail’s belly, to the time she is ready to give birth.
She can give birth over a few days because swordtails give birth to around 150 fries.
How Many Times Can A Swordtail Give Birth?
A swordtail can give birth up to three times a year. Aswordtail fish is ready to give birth as soon as she drops her fry from the previous pregnancy.
Swordtails can also give birth without a male swordtail partner because of their ability to store sperm.
Conclusion
Swordtails usually give birth at night, while they sometimes do not. We don’t know why this is the case. Perhaps their circadian rhythms dictate that they should give birth when it is dark out?
Whatever the reason may be, there are some signs that your swordtail might be ready to give birth and you should keep an eye on her.
