Platies and Mollies are both species of fish found in tropical aquatic environments and they produce their offspring alive. They also belong to the same family, the Poeciliidae. Both species are widely sought after by aquarium enthusiasts due to their vibrant colors and high activity levels. On the other hand, distinguishing between the two can be difficult, which is why we’ll look into how to tell a Molly from a Platy in this article.

The size and shape of a Platy fish can be used to differentiate it from a Molly fish. Mollies have a longer and larger physical size, ranging up to 4.5 inches (11-12 centimeters), while Platies have a shorter body size and a rounder shape. Also, their maximum length is usually about 2.8 inches (7,5 centimeters).

The most significant distinction between the two is that a Platy and a Molly come from separate species. Because the Molly is a member of the Poecilia species and the Platy is a member of the genus Xiphophorus, the two species are incompatible for reproduction. Continue reading if you are interested in finding out who belongs in the Molly and Platy families and how to differentiate between them.

What Is a Molly?

Molly, or Poecilia sphenops, is an aquatic fish species. It is also known as a typical Molly and a short-finned Molly. Mollies were once classified in the genus Mollienesia but are now part of the Poecilia family.

How To Tell a Molly From a Platy?
How To Tell a Molly From a Platy?


The Sailfin Molly originates around the southeast coast of the United States and the Gulf of Mexico. At the same time, the familiar Molly can be found from Mexico to the northern parts of South America. The sailfin, sometimes known as the Yucatan Molly (P. velifera), is endemic to the Yucatan Peninsula in southeast Mexico.

The Molly is said to first appearing in the hands of recreational fish tank hobbyists in 1899, and its popularity has only increased since then. When compared to other Poecilia species, such as the guppy and the Platy, Mollies are known to be more belligerent. Hybrids within the Molly family come in a wide range of colors and can be broadly classified into three groups based on whether their fins are short or long.

Molly Varieties

There are a wide variety of sizes, shapes, and colors seen in Molly fish.

·      Black Molly.  

These all-black Mollies are popular because of their resilience and ability to produce offspring quickly.

·      White Mollies 

White Mollies are distinguished by their all-white appearance, which draws attention to their huge, black eyes.

·      Golden Molly

Hobbyists adore Golden Mollies because of their gleaming gold or 24-carat sheen.

·      Balloon Molly

The peculiar look and unusually curved spine of Balloon Mollies result from a genetic abnormality.

·      Lyretail Molly

The caudal fins of these stunning Mollies are very long at both ends. It’s shaped like a lyre and extends beyond the fin’s midsection.

·      Dalmatian Molly

The body of a Dalmatian Molly is white, and the spots are striking jet black.

·      Gold Dust Molly

These mollies, known as Gold Dust Mollies, have short fins and a dusty gold and black color scheme.

·      Creamsicle Lyretail Molly

The expanded dorsal fin of a creamsicle lyretail molly combines orange and white.

·      Harlequin Sailfin Molly

The Harlequin Sailfin Molly is a unique species of Molly with an orange body and a gold, white, and black harlequin pattern over its fins and body.

·      Marbled Lyretail Molly

The black and white marble pattern on the body and fins of these fish is stunning.

What Kind of Qualities Does Mollies Possess?


Mollies in the wild are typically a dull silver, but mature males can be a striking blue-green. Spots are visible on their sides, backs, and dorsal fins and can sometimes grow to cover the entire body. The wide spectrum of hues seen in members of this species includes silver, black, and yellow-orange.

A small, flat head with projecting teeth is a tool to scrape algae from surfaces, and their bodies are elongated. The outer row of teeth is the larger of the two.

The molly has a robust, stocky body and a rounded, convex tail with sharp dorsal fins.

As a distinguishing feature, their mouths are angled steeply upward. Their genetic makeup gives them a mouth that turns upward to sip oxygen from the water’s surface.

Male Mollies are smaller than females and have a gonopodium that sets them apart. These rod-shaped reproductive structures, called anal fins, are utilized by male Mollies to mate with females. Both sexes are very busy, and the males, in particular, can sometimes be aggressive. Because of their diurnal lifestyle, they are most active during the day.

The Female and Male Molly

Female Mollies are more slender and have smaller fins than their male counterparts. A male molly’s reproductive organ is as mentioned a stick-like structure called a gonopodium, formed by a modified anal fin.

In general, Mollies are simple to breed.  Due to their aggressive breeding habits, a male-to-female ratio of 1:3 is recommended in the aquarium to avoid stressing the female inhabitants.

After a productive mating, mollies may retain sperm in the body for months and have up to five litters of live young. Sailfin mollies is reported to have anywhere from 20 to 150 offspring in every litter.


Mollies are generally peaceful creatures that live their lives in groups. They may become aggressive when their tank’s male-to-female population ratio is off. While it’s true that male Mollies can engage in reproductive harassment, this isn’t usually an issue if there are enough females in your aquarium.

What is a Platy?

How To Tell a Molly From a Platy?
How To Tell a Molly From a Platy?

The Platy is a live-bearing fish belonging to the family Poeciliidae. The name Platy was derived from an older categorization known as Platypoecilus, derived from the Greek term “flat” or “wide.”

Platies are fish species native to Mexico’s southern regions and Central America’s eastern coastline. There have been several different hybrids produced by crossing the Variable Platy (Xiphophorus variatus) with Southern (Xiphophorus maculatus), and frequently the uncommon Swordtail Platy (Xiphophorus xiphidium) has been included in the mix to produce a broader range of fin forms.

All of the above three species can hybridize with one another, which is one reason why the Platy we recognize today is a combination of three different species. The Southern Platy and the Variable Platy are similar in appearance; they are both small and stocky and have a wide range of coloration. Red, yellow, green, and blue are the colors that are the most popular among enthusiasts today. It is believed that these hues arose as an adaptation to their natural surroundings.

  • Southern Platy is the ancestor of several well-known breeds, including Coral, Comet, a Half Moon, Salt & Pepper,  Blue mirror, and Moon.
  • Variable platy includes Marigold, Yellowtail, Redtail, Rainbow, Sunset, and Hawaii.

Platy Varieties

The species that go into making up the Platy species have many mixes between them. Therefore, many of the specimens sold in the marketplace are hybrids. Several different Platies have been produced to achieve specific color qualities, including the following:

·      Wagtail Platy:

The wagtail comes in a few colors: red and gold. Other less common colors include blue and green.

·      Variegated Platy: 

The slashed paint look, also called “painted platies,” can be coupled with several different colors or tail modifications, including the Mickey Mouse Platy.

·      The Salt and Pepper Platy: 

The Salt and Pepper Platy:  An eye-catching look can be achieved by applying this effect over several different Platy body colors.

·      Tuxedo Patterned Platy

This look is a fascinating version of the platy color, called the tuxedo pattern. In this pattern, the back part of the fish is black, while the front is a different color. Tuxedo versions blended with the red and golden body color are the most popular, although the effect may be achieved on a wide range of Platy colors.

·      Comet pattern Platy

They are also known as the twin bar pattern, distinguished by the presence of two black stripes, one on either the left or right side of the caudal fin. The striking stripes draw attention to the various colors of the fins and help them stand out visually. There is a possibility that these differences will manifest themselves in the Platy’s multiple colorations.

·      Hi Fin Variety 

The dorsal fin in the Hi Fin variety is more prominent and extends higher than it does in ordinary Platy fins in the Hi Fin version of the Platy fish. This variety can be found on Platies of many different colors, and it can also be coupled with the wagtail coloring of some.

·      Pintail Platy Fish:

The pintail variety is less prevalent. It can be easily recognized by the elongated center region of the tail fin that extends conspicuously from the tail fin. Pintails set themselves apart because the pintail variation is less common.

Characteristics of a Platy

Some essential features of platy fish are given below;

Appearance of Platies

Platys are tiny and laterally flattened, implying that they appear narrow or flattened when viewed upward. However, when looked at from the side, platys seem to be as expected. They have relatively short and compact fins and a tail that is basically in the shape of a fan. 

The Southern Platy, also known as Xiphophorus maculatus, has a length of around 2.8 inches (7 centimeters). The male, as mentioned, has a dorsal fin which is more pointy than the female, and a developed gonopodium, an organ in the shape of a stick employed for breeding purposes. It is simple to tell a female Platy from a male because the anal fin of the female is shaped like a fan.

In the wild, the Xiphophorus variatus Platy has a body hue that resembles olive with black spots that seem like marble. Compared to its southern relatives, the variatus is often longer and thinner. It also has a more elongated body. They typically have 12 dorsal rays and two rows of jaw teeth.

Platy Behavior

They coexist peacefully with mollies, guppies, and swordtails in the same aquariums. However, if there is an imbalance in the number of males to females or if there are changes in their habitat, they have the potential to become agressive. They might also show aggressive behavior if there are too many other fish in their tank or not enough places for them to hide.

Platies are a joy to breed and attain sexual maturity at a young age, barely four months old on average. They have such a rapid reproduction rate that they can swiftly take over your tank if you let them. Because they are such prolific breeders, you should ensure at least two to three females for every male to reduce the likelihood of stress among the female population.

Because platies do not make perfect parents and frequently consume their fry, some caution is required during the birthing process of new fry. The gestation period of a female Platy lasts between 24 and 30 days on average, and while she can deliver anywhere from 20 to 80 live young at once, in most cases, she will only produce 20 to 40 babies.

Female vs. Male Platies

If you examine the underside of the Platies’ bodies, you can tell the gender of the Platies. The anal fins of females are fan-shaped, whereas the gonopodium of males are pointed and lengthy, and they are usually kept in a position that is quite near the body. Males are easily identifiable by their more vibrant coloration and larger dorsal fins.

How To Tell a Molly From a Platy?

The Platy and Molly varieties are distinct from one another in various ways, including their personalities, biology, and appearance. A few key distinctions, when you’re wondering how to tell a Molly from a Platy, are:

  • Mollies come from the genus Poecilia, while Platys are classified under Xiphophorus.
  • Mollies typically show bright hues, including orange, green, black, and white.
  • Warmer tones are typical of platies, which may be spotted and come in various colors, from orange and red to white and gold.
  • Male Mollies typically grow to an aggregate of 3.2 inches (8 centimeters) and female Mollies to a total of 4.8 inches (12 centimeters), while Platy fish grow to an average of 2.8 inches (7 centimeters).
  • Mollies are characterized by a more rounded, compact body type with an upturned mouth.
  • They can’t mate since their DNA is too different.


It can be challenging for the common eye to identify a Molly from a Platy. You should know your Platies and Mollies‘ exact sizes and colors because the genetic differences and characteristic gonopodium can be difficult to see.

So, hopefully the article above is helpful the next time you’re wondering how to tell a Molly from a Platy.