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Platies vs. Mollies (Their Similarities and Differences)

Platies vs. Mollies (Their Similarities and Differences)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Fish enthusiasts usually compare platies vs. mollies. This is due to their similar physical characteristics, habitat requirements, and behavior.

They’re both popular species often kept as pets because of their appearance, active behavior, and easy-care requirements. Although they’re both part of the Poeciliidae family, they have distinct characteristics that set them apart.

In this article, we’ll explore those differences and similarities. We’ll also guide you on their preferred habitats, diet, and care requirements. If ever you’re in the market for new pet fish, this guide is for you!

Physical Characteristics

Platies and mollies are both known for their small size and vibrant colors. Although both are popular species, there are notable differences between their physical appearance and characteristics.


Both the platies and molly are relatively small species of fish. Platies grow to around 2–3 inches in length. Meanwhile, mollies can grow between 3–4 inches.


Looking from afar, the platy and the molly may look similar. However, up close, you’ll notice that they have subtle differences in appearance.

First, the platy has a slightly elongated body shape, with a rounded belly, a pointed snout, and large triangle-shaped dorsal fins. They also have fan-shaped or rounded tail fins.

Platies are known for their wide range of colors, which includes red, orange, green, blue, black, and yellow. These colors often come with patterns, like stripes, spots, or patches.

On the other hand, mollies are characterized by their sleek, elongated bodies, with a flattened belly and an upturned mouth. Both of their dorsal and anal fins are pointed and long.

Their caudal fins are fan-shaped, slightly flared-out on the top and bottom, making them look forked.

Further, their coloration and patterns are more uniform and have fewer variations than that of platies. They come in various colors and patterns, including silver, gold, and black.

Are Mollies and Platies Related?

Both species are related since they’re part of the Poeciliidae family. However, they differ in general.

Platies belong to the genus Xiphophorus, while mollies are members of the Poecilia genus.

Can Mollies and Platies Breed?

As part of the same family, both fish are known to be livebearers, made possible by a specialized fin in males called the gonopodium. It helps transfer sperm cells from the male to the female during mating.

In general, fish can only crossbreed with closely related species. This means that two fish species should belong to the same genus for successful mating.

Since platies and mollies belong to different genera, they cannot breed naturally as their genetic makeup is too different to produce viable offspring.

Habitat and Tank Requirements

In this section, we’ll explore the natural habitats and specific water conditions each species prefer:


Platies are found in freshwater streams on the east coast of Central and South America. Their streamlined body shapes help them navigate and maneuver through the water.

They thrive best in warm, tropical water with temperatures between 70–82°F and slightly alkaline pH levels between 7.0 to 8.2. Aside from this, they prefer a water hardness of around 12 to 35 dGH.

The platy can adapt to many water conditions, whether on slow-moving or still water. Ideally, platies can thrive best in an aquarium with some water current, as their natural habitats are streams and rivers.


The molly fish is native to the Southern United States and Colombia. Mollies, compared to platies, can survive in varied salinity levels and a wider range of habitats.

They’re often found in either freshwater or saltwater environments such as ponds, mangroves, and streams. This makes them more adaptable in different aquarium setups.

Regarding water conditions, mollies prefer temperatures of around 75–80°F. They also thrive best in waters with pH levels between 7.5–8.5 and water hardness of 12–25 dGH.

Diet and Feeding Habits

In the wild, both platies and mollies share similar dietary needs. They feed on plant matter and protein-rich food, such as algae, small insects, crustaceans, and worms.

However, in captivity, it’s vital to feed them a balanced diet to meet their nutritional needs. They can be fed various commercial foods, like flakes and pellets. In addition to this, they can also consume frozen food, such as bloodworms or daphnia.

Specifically, platies are easier to feed. They can consume commercial and frozen food, along with tiny portions of vegetables. Additionally, they can graze on algae and other plant matter in their aquariums.

Mollies, on the other hand, require a protein-based diet, including small crustaceans, insect larvae, and worms. Further, they can benefit from algae wafers and spirulina. Additionally, they can feed on vegetation in their tanks.

It’s essential to provide them with enough food they can consume in one meal. Further, it’s recommended not to feed them more than twice a day. This is because both species are prone to obesity and digestive issues when consuming excessive amounts of food.

Behavior and Temperament

Both platies and mollies are friendly and social fish. They’re also known for their active behavior. In an aquarium set up, they can live peacefully in groups or with other fish species.

Can Mollies and Platies Live Together?

If you’re planning to keep platies and mollies together, they’re able to coexist peacefully in the same tank as long as their needs and care requirements are met.

Aside from providing them with a proper diet, it’s essential to provide a wide enough space and several hiding places in the aquarium. Additionally, the water parameters in the tank should be compatible with both species.

To maintain a peaceful community tank, it’s recommended to avoid mollies and platies with aggressive fish like bettas.

Are Mollies or Platies Better?

Platies and mollies have a lot of similarities, so determining the better breed can be tough. Ultimately, it’ll come down to your preferences and your ability to care for them.

Although both species can cohabit with other species, they may display different behaviors.

Platies are peaceful fish and they prefer to live within small groups. However, they may show distress if they feel threatened or overcrowded.

Female platies are docile and are social towards each other. Male platies, on the other hand, occasionally display hostile behavior during mating season.

The same behavior can also be seen towards male mollies. They tend to show aggression by nipping, chasing, or getting territorial toward other males.

To avoid this, keep only one male within a small group of mollies.

Additionally, mollies are more territorial and may nip at the fins of other fish when stressed. They’re best kept with peaceful fish species such as tetras, minnows, and rosy barbs.

Health and Care

Platies and mollies are relatively easy to care for. However, like other pets, they require proper care to thrive and stay healthy.

Water Quality

Keep your platies and mollies in well-maintained and well-filtered clean water. It’s vital to monitor that the water is at the right temperature, pH, and hardness level. You can use a water testing kit to maintain the proper water parameters of your tank.

Tank Size

A good rule of thumb is to keep a small group of fish in a 10-gallon tank. Doing this will give your fish plenty of space to swim around, be active, and grow.

Tank Mates

To avoid any hostile behavior and fighting between your fish, it’s essential to keep them together with compatible tank mates. Both species are pretty laid-back, and keeping them with species of the same size and temperament allows them to live peacefully.

Tank Maintenance

It’s vital to ensure that your tank peripherals are working. Regularly check pumps, filters, and lights for any malfunctions. In addition to this, you also need to clean the tank glass and other structures at least once a month or as often as needed.

Final Thoughts

Both platies and mollies have become popular and easy-to-keep freshwater species. While they share some traits such as their temperament and dietary needs, they differ in appearance and preferred habitat.

Like any other pets, they should be provided with a suitable environment and care while in captivity.

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