Platy fish care guide

Unpretentiousness, beauty, various coloring patterns, easy to breed – this is all about platy fish (lat. Poecilia). This fish is like guppy, swordtail fish, molly fish – it is a live-bearing one, i.e. it carries eggs inside its body and spawns completely formed ready to swim juveniles. In this article we’ll tell you about platy fish care and breeding.

Habitat in the wild

Poecilia family encounters about 170 species of various colorful fishes dwelling in different waters of South, Central and North America. All the family species are divided into 26 genus.

The platy fish was first brought to Europe in 1907 from South Mexico and Guatemala, where they live in lower reaches of rivers flowing into Atlantic Ocean. In the wild platy fish coloring is ochrous (brown and yellow) with two dark spots in front of its tail fin. Nowadays, there are lots of selection breeds of the fish, that have miscellaneous coloring and fins shape.

Scientific NamePoecilia
Common NamesPlaty; platy fish
Range and habitatSouth Mexico, Guatemala
Size1.5-2.5 inches (4-6 cm)
Lifespan3 years
Ease of keepingEasy
Minimum tank size13 gallons and more
Temperature21–27 °C (70–81 °F)
Water hardness5-20 dGH


The platy fish size is 1.5-2.5 inches (4-6 cm), females are larger than males. They have short, fat body and strong wide tail fin. Adult males have a modified anal fin, it looks like a tube and this is their organ of generation called gonopodium.

Platy fish lifespan is about 3 years. There are several dozens of the color variations, it is just impossible to describe them all. As an example, we can mention disk platy fish – a specially bred fish with curved spine due to which it has a specific body shape.

disk platy fish

Difficulties in keeping

The platy fish is good both for beginners and professionals. Everyone can find among them interesting species to keep.

Keeping in a tank

Let me mention, that frequently Poecilia dwells with other live-bearing fishes in a tank – with swordtail fish, for example. The problem is, that they look very much alike in the wild, plus the number of hybrids, that have appeared recently… the author of this article has lots of platy in his tank and sometimes he doesn’t know if these are platy or swordtail. Especially, if there were just 1-2 fish. Luckily, these fishes require identical tank conditions and care.

Almost like all live-bearing fishes, platy isn’t demanding and is good-tempered. You can keep them in tanks with capacity starting from 13 US gallons (50 liters), but it’s better to have a larger tank.

They don’t demonstrate aggression towards its kind (unlike swordtail) and you can keep them in the ratio where females number is larger. One male is for 2-3 females.

Tank water parameters aren’t that crucial. Water should be of medium hardness (5 – 20 dGH), acidity within ph: 6.5-7.5, water temperature 21–27 °C (70–81 °F).

Water should be clean and fresh. It is required to perform up to 20% water renew every week. Filtration and aeration are desirable, but if the tank isn’t crowded you can skip it.

Compatibility and tank mates

Platy is compatible with all peaceful fishes, especially with fishes from the same family: guppy, swordtail fish, molly fish etc.

Unlike swordtail males, platy males are friendly excluding some small fights for a female attention. To avoid this, you should have approximately equal number of females and males in a tank.


In the wild platy fish feeds on insects and algae. In a tank it eagerly eats any type of food. It is important to include vegetable components into the diet.

These may be both flakes with vegetable supplements and boiled vegetables – cucumbers, squash, spinach.

In the wild algae composes a large part of the diet as well as it aids its gastroenteric tract. Therefore, the platy fish likes food with high content of vegetable fiber.

Gender differences: male vs female

Gender dimorphism of poecilia male and female is rather strongly pronounced. Females are usually significantly larger, with round and fat abdomen, they are less brightly colored.

Male’s anal fin has turned into gonopodium, it is small and sharpened, while the female’s anal fin is wider. Also you can see, that males are more active, they are always haunting females.


You don’t need to perform any special preparations, this will happen just if you have a male and female in the tank. Platy become reproductive at the age of 5-6 month. The fish can carry eggs for 1.5 month and longer.

According to my observations, the platy fish offspring is quite small in number. For example, I have 2 females in my tank and one of them had 15 juveniles and the other – 26.

You can easily define pregnant poecilia by its fat abdomen. If the abdomen skin is transparent enough, you may even see black juveniles eyes.

Only visually you can try to get, when the platy fish is going to spawn for the first time. Then at the second time and further you will be able to determine quite precisely when this is going to happen.

Shortly before spawning the abdomen becomes a bit angular shaped. You should put the platy fish into a spawning tank to prevent spawning in a common tank, where the juveniles will be eaten.

Juveniles are born very much alike swordtail juveniles. But 1-2 weeks later they become different. They have fatter and shorter body and two small black spots on both sides of a tail fin insertion edges.

It is easy to care about the juveniles, since they are born quite large and ready to swim. You can feed them with egg yolk, dry food, branded food for juveniles.