Pregnant Platy Fish – Is Female Platy Fish about to Give Birth?

If you’re about to breed platy fish, you may want to take a moment to familiarize yourself with the aspects of breeding platies, knowing how to tell if your platy fish is pregnant, and knowing how to take care of platy fry.

I’ve put together this guide on platy fish pregnancy and breeding, so it can serve as a basis for your research on platy fish breeding and platy fish fry.

By reading this article, you will have a better understanding on how platy fish breed, how to know if your female platy is pregnant, and ways you can manage the resulting fry.


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Let’s get right to it!

1. How Platy Fish Breed?

Good news for those wanting to breed platy fish: Platies are very easy to breed. There are no special prerequisites other than setting up a suitable habitat, having both male and female platies in the aquarium and letting nature follow its course.

Platy fish are live-bearing fish and give birth to live fry unlike egg-layer fish, which lay eggs, fertilize them and hatch them outside the body of the female fish.

Platy fish produce eggs that are fertilized by the male platy while the eggs are still inside the female. Hatching also occurs in the belly of the female platy. When the eggs hatch, the female releases the fry into the water.

Although still small, baby platies are fully-formed and capable of swimming and feeding right away, which makes it easy to care for them.

There are a few things to know about reproductive age, determining the gender of platy fish, and stocking the aquarium with the right number of male and female platies.

Platies are ready to breed at 5-6 months of age. Female platy fish are larger than male platies and they have a rounded abdomen. There are also differences in color, females being less colorful.

The anal fins of male platies will turn into a gonopodium, which is the reproductive organ that will fertilize the eggs. Female anal fins are wider.

You can place a single male platy and a single female platy in a breeding tank and expect that they’ll successfully breed, however, make sure that there aren’t more males than females.

In live-bearing fish, male fish usually chase around the females to reproduce, which can stress out female fish. This is the reason why the one male to 2-3 females stocking ratio is the gold standard with these fish.

After fertilization occurs, the female platy will bear the eggs for one or one and a half months. She will produce between 20 and 80 juveniles and can reproduce as frequently as every month or so.

Platy fish — as many other livebearers — engage in filial cannibalism, which simply means they’ll eat their juveniles mistaking them for food.

The only way to save juveniles is to remove adults as soon as the platy female releases them into the water.

2. How to Know if Platy Fish is Pregnant?

One of the first steps in preventing adult fish to eat baby platies is to know how to recognize the signs of pregnancy and prepare the aquarium for the time the female platy will give birth.

After copulation, it will take a couple of weeks for physical signs of platy fish pregnancy to appear. During the gestation period, the abdomen of the female platy will become enlarged and she will develop a dark spot on her belly, which signals that she’s pregnant.

You can write down the date your first notice the pregnancy spot, so you can better approximate when she’s about to give birth.

3. Is Platy Fish About to Give Birth?

To prevent platy adults from eating baby platies, you must take some precautions before the female platy is about to give birth.

But how can you tell if she’s preparing to give birth? Are there any signs?

If you know when reproduction occurs and when you first noticed the signs that your platy fish is pregnant, you may tell that she’s preparing to give birth by how much time has passed since copulation, but also by monitoring physical traits and behavior.

You may notice that as she’s preparing to spawn, the abdomen of the platy fish becomes angular. She’ll also be seeking out darker and more covered places of the aquarium.

This is your cue that you need to act fast to prevent her from giving birth in a community aquarium.

4. How to Save Platy Fry?

So, if you want baby platies to survive, you must save them from hungry or curious adults.

There are three methods that you can use to prevent carnage in your aquarium:

Setting Up a Separate Tank

By setting up a breeding tank, you can easily remove the males after reproduction and remove the female as soon as she gives birth, all the while continuing to care for platy juveniles.

With a separate tank, you must be careful to match the water parameters of the original tank.

Installing a Breeding Box

A breeding box is an easier way to save platy fry. All you need is a breeding box, which will prevent adult fish from getting in there and eating platy fry.

With a breeding box, water parameters are already a given, and you needn’t worry about matching them in a separate aquarium.

You shouldn’t keep baby platies for more than 2 weeks in the breeding box since it will stunt their growth.

Having a Heavily Planted Aquarium

Now, you may not want to invest in a breeding box, nor are you considering setting up a separate aquarium, especially if your aquarium is already large enough as it is for your platies.

If it’s also heavily planted, the plants may be enough to offer sufficient cover to hide platy fry from the adults.

I personally prefer setting up a separate breeding tank, then removing the adults once the female releases the fry.

If you’re seeking to commercially breed platies, allowing them to remain in the aquarium with the adults — even a heavily planted one — may not be your best option from the ones I presented above.

5. What to Feed Baby Platy Fish?

Now that you’re left with caring for baby platy fish, you must know what to feed them to help them grow and stay healthy.

Luckily, it’s not difficult to raise baby platies or to feed them, especially that they have a great appetite.

As omnivorous fish, they’ll accept all fish foods, however, at the beginning, you will want to up their protein intake to kick-start their growth.

Baby brine shrimp, daphnia, vinegar eels, micro worms are all good options and so is fish flake food, just make sure to crush it into a powder to make sure it fits their mouths.

Feed platy fry often with small amounts all the while taking care not to foul the water.


Breeding platies is a breeze compared to other fish that require conditioning and special measures to breed.

You may not be able to tell if your platy fish is preparing to give birth the first time around, but if you monitor her closely, you’ll soon get the gist of it all and with time, you’ll be able to spot the signs early on.

I hope this article will serve as a good basis for breeding platies and caring for platy fry.

Questions and Answers

Pictures of things like the angular abdomen, the dark spot on the belly when pregnant, and possibly the difference between males and females, showing the most colorful that females tend to be in that comparison, would turn this article from good to great.

With those pictures I would feel I had everything I needed, versus having just enough to maybe catch on.

That said, good article,thanks for the help, and (hopefully) reading this comment.

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