The fish is relatively easy to look after because of their hardy nature, which can tolerate wide range of water parameters. The condition for them to live in should be similar like those provided for any freshwater tropical fish whereby temperature is around 24 to 28deg Celsius while pH can be within 6 to 8. In terms of tolerance to high nitrite and nitrate levels, they can withstand fluctuations much better than any other fish and because of that, platies are always used as starter fish for beginner's tank.
Breeding platies are rather straight forward and most of the time, it will happen on its own without your intervention and provided that the living condition is at its best with good water quality and huge tank space area. A good practice to successfully breed the fish is by outnumbering the males with females using ratio of 1 to 3, meaning that let’s say if you have 2 male platies, the number of females should be 6. This way, it will ensure that there is no in-fighting or occurrences whereby the male will chase the female platy until it become exhausted as this could be life-threatening to your pet fish.
A reliable method of determining whether you have a male and female platy is by looking at the anal fin. A female platy would have the fin fully opened while for male platy, the fin is closed to become a long straight pointy fin called gonopodium, which is used to inseminate the female fish. Pregnant female platy can be easily identified by looking at the size of the belly, which begins to darken at the area right above the anal fin.
Platies are live-bearers meaning that the fish doesn’t lay eggs and will release free swimming fry. Usually the pregnancy period can be anywhere between 3 to 4 weeks and during this period, the fry will actually consume the yolk sac and become fully developed in the womb of its mother. Platies are notorious for eating their own babies and in order to ensure that the fry have high survival rate, you can actually overcome this by setting up an aquarium tank full of plants and vegetation to provide a good hiding spot. Predation is a natural process but if you want to ensure that every single fry survive, you can use a fish breeding trap or hatchery which has a compartment to separate the fry.
Caring for platy fish fry can be extremely easy. By the time, they are born, the size is anywhere between a quarter to half centimeter and they are known to be an active swimmer. Once they are released into the water from their mother’s womb, they will immediately dash to a hiding spot and will swim away if there’s any movement of any object approaching them. These free-swimming fish fry will readily accept any food you feed to them.
You can either soak your normal fish food with water and then crushed it until it becomes diluted powder or you can use hard-boiled egg yolk. These days, there are even liquid fry foods, which you can buy from aquarium pet stores and all you have to do is to add a drop of the liquid into the water. Despite the availability, the recommended nutrition should still come from brine shrimp nauplii if you intend to provide the best for your pet. Finally if everything is well taken care of, the young fish fry should achieve full-grown size in about 4 and a half months to begin another cycle of breeding.
Updated February 2014
One interesting question sent in by a reader of All About Aquarium Fish which thought would be best to share it here
Question: Hi, I was looking up some info about platies. Though my question was partially answered by the information article I still seek further clarification. I have two full grown females that were purchased eleven months ago. One, (red wag) has given birth once that I know of. The other (yellow with black stripes on tail fin) is currently in the midst of her third known pregnancy. I currently have six surviving fry of various sizes. I saw a reference to around four months old and they are old enough to breed. Is that correct? Also, on average about how often could very active platies breed in a year?? My tank info if interested is: 55 gallon tank, three algae eaters (smaller varieties currently 2.5 to 3.5in., three red blue tetra, two black skirt tetra, four full grown, one juvenile, and five fry platy. I love my tank and my fish. They are very entertaining. Thank you for your time.
Answer: Based on my own experience, female platies are able to conceive by the time they are 4 months old. Few interesting facts about platy breeding that I want to add further.
1) Depending on age and size, female platies generally give birth to fry numbering between 20 to 40. Average adult, I would say about 30. Note: Young female platy at 4 months old can only give birth to about 3 - 5 fish fry from their small belly. Try to observe carefully
2) Platies mature faster when placed in a tank together with the other larger adult platies. Make sure your food is sufficient, enough for everyone. They get influenced by the actions of the older fish. I hope you get what I mean here... the mating dance
Related Topic: Learn how to identify & naming different platy types