The molly is a popular aquarium fish and can be seen in the displays of stores that specialize in selling aquatic life. There is more than one species of molly. Several kinds and varieties of mollies are popular additions to home aquariums.
The fishes themselves often have very attractive appearances. Due to their low maintenance requirements, molly fish are a popular choice for household aquariums. There are many different molly fish species, and each has its own unique pattern of colors, yet they all share a gentle disposition. Popular mollies can be broken down into three distinct groups: the natural molly fish, the selectively produced sailfin molly, and the selectively bred lyretail molly.
Learn about the several species of Mollies before deciding to bring one home or purchase for a community aquarium.
Different Types Of Molly Fish
The Molly Fish genus includes a dazzling array of forms, sizes, and colors. Since Mollies and Guppies have been interbred for so many years, we see a wide variety of physical traits among the offspring of these two species. Different species of Molly Fish have their own distinct characteristics. They might both be brown, but one could also be crimson or black. Oftentimes, their name will give you some insight into their appearance.
Among the common varieties of Molly Fish are:
Black Molly
The term “Black Molly Fish” reflects the actual color of these fish. However, this is not always the case, as some Black Molly Fish may actually have a single yellow stripe along the length of their body. Because they are often bred in aquariums, Black Molly Fish are not commonly seen in the wild.
Care Difficulty
Give them plenty of room to swim and explore the tank, and add some plants for aesthetic value. The Black Molly is a beautiful and low-maintenance pet. They don’t have high maintenance needs, so you don’t have to babysit them.
Temperament
The black molly fish is a community fish that gets along well with other fish of the same placid disposition.
Fish Size
Male black mollies reach a maximum length of 3 inches, but females can go a bit bigger than that (often a couple of extra inches).
Food & Diet
Black mollies can be fed almost anything, so you probably already have everything you need on hand to care for one. If your tank is prone to green algae outbreaks, adding some Black Mollies will help keep the problem from becoming any worse.
Water Condition
Keeping Black Mollies requires water that is between 70 and 80 degrees Fahrenheit, with a pH that is closer to the harsher, more alkaline side of the spectrum (7.5 – 8.2).
Because of their extreme sensitivity to environmental fluctuations, mollies require a stable tank environment at all times.
Tank Mates
Generally, black mollies get along fine with other types of livebearers. Guppies, Danios, Tetras, other Mollies, Swordtails, Gouramis, Platies, and even female Betta fish have all coexisted peacefully with our Black Mollies.

Dalmatian Molly Fish
The spotted bodies of Dalmatian Molly Fish make them a popular pet. As their name suggests, they share a color scheme with the dalmatian. Both of them have black dots scattered across their white bodies. Sailfin mollies are the presumed ancestors of the Dalmatian molly.
Care Difficulty
Mollies are low-maintenance pets that require little attention. Many Dalmatian mollies meet an untimely end because of inadequate housing conditions like small tanks and bowls.
Temperament
Dalmatian mollies are often quite docile and show no signs of aggression. But it’s not clear to say that all Dalmatian fish are usually peaceful. Despite the fact that a sizable minority of them can be exceptionally nice.
Fish Size
Female mollies tend to be greater in size than male Dalmatian species. Female dalmatian mollies can reach a maximum length of 4.5 inches (12 cm), with males topping out at 3 inches (7 cm) (8cm). Their offspring are typically approximately a half an inch long. They are large enough to coexist peacefully in a community aquarium with fish of different species.
Food & Diet
Dalmatians, being mollies, are omnivores just like any other molly. They gravitate strongly toward plant life. Additionally, they are extremely picky about the algae that develop on aquarium plants. In addition, there is a great selection of meals available. To name a few examples: pellets, freshly blanched crops like spinach, and frozen items like mosquito larvae.
Water Condition
Similar to other mollies, Dalmatians’ water accounts for both the water’s temperature and its acidity. Mollies, in general, require hard water with a high PH (slightly alkaline).
They prefer a tank environment of 70-82 degrees Fahrenheit, 7-8 pH, and 10-25 dH.
Tank Mates
Active yet potentially dangerous fish, Dalmatian mollies can bite if provoked. That’s why it’s not a good idea to house them with other fish species that have long fins. They also don’t lay eggs, as they are livebearers. In that case, they can be used for a variety of other livebearing species. Guppies and Cherry barbs are good choices for mollies’ tank mates.
Sailfin Molly Fish
The dorsal fin of a sailfin molly fish is so distinctively shaped that it inspired the fish’s common name. The Sailfin Molly Fish gets its name from the way the tip of its dorsal fin is shaped, yet there are variations of this species that look much like other Molly Fish.
Care Difficulty
Sailfin Molly is a lovely fish that requires little attention. To properly care for sailfish, all you need to do is feed them a diet high in algae and a small amount of brine shrimp flakes.
Temperament
The sailfin molly is a gentle and placid kind of molly. It’s not harmful to anybody else. However, others do due to its little size. Large predators include frogs, raccoons, alligators, and gigantic water bugs.
Fish Size
The sailfin is a tiny fish. Males reach sexual maturity before females and have a higher mortality rate in the year after this milestone. If given optimal conditions, their maximum growth period is three years. In this window, they can grow to between 7 and 15 centimeters in length.
Food & Diet
Because of their omnivorous diet, sailfin mollies can consume both plant and animal matter. Sailfin mollies eat a wide variety of foods, including plankton, zooplankton, insects like mosquito larvae, and detritus like flakes and pieces. Flake cereals are among the most popular foods.
Water Condition
The sailfin bream is extremely sensitive to changes in water quality. The warmest waters are ideal for sailfin fish. Sailfin fish thrive between 25 and 30 degrees Celsius. Sailfin fish are completely at home in both fresh and saltwater. Mildly alkaline conditions are ideal for it. Therefore, a pH between 8.1 and 8.4 is ideal for sailfin fish.

The Balloon Molly Fish
You may usually find Balloon Molly Fish, also known as Belly Molly Fish, in streams and other bodies of slow-moving water in the Americas. Once you have a good look at them, you’ll quickly understand where their name originates from. Like Sailfin Molly Fish, the names of these fish simply give a general idea of their body form rather than the actual colors they may be. As their name suggests, Balloon Molly Fish have bloated bellies that occasionally make them look like balloons.
Care Difficulty
Balloon belly molly fish (Poecilia sphenops) are stunning additions to any home aquarium not only because of their unusual appearance but they are also wonderful for beginners because of how simple they are to care for and how beautiful their tank will appear as they swim from one end to the other.
Temperament
Because of their calm demeanor, mollies are able to live together with a wide variety of different fish, crustaceans, and even snails. Because of their sociable nature and tendency to travel in schools, Balloon Mollies do best when kept in a community aquarium.
Fish Size
When compared to other molly fish, such as the giant molly and the spotted molly, the balloon molly is the smallest of the bunch. Adult mollies average around 3 inches in length (or around 7–10 centimeters), with a maximum size of about 2 inches.
Food & Diet
Balloon mollies are omnivores, meaning they eat a wide variety of things, including meat. Besides plants and algae, tiny invertebrates are one of the main foods for Molly fish in the wild. Balloon Mollies in an aquarium can be fed flakes, pellets, and algae wafers; for variation, you can also give them little pieces of lettuce, zucchini, and spinach.
Water Condition
Since they are tropical fish, the water must be kept between 65 and 82 degrees Fahrenheit and between 7.0 and 7.8 pH to ensure their health. For this reason, it is necessary to equip the aquarium with a heater. Get a PH test kit to make sure the water is at a safe level. The pH of my water is something I keep an eye on once a week at the most.
Tank Mates
Even though balloon belly molly fish are relatively docile, it’s best to keep them in a tank with only their own kind. They might harass less powerful fish and nibble at their fins. It’s also not a good idea to keep them in a tank with big fish or fish that are known to be aggressive. Male fish are known to harass females; therefore, it’s best if the shoal is predominantly female.
The Lyretail Molly Fish
The body shape of a certain species of Molly fish is reflected in its common name. As its name suggests, the Lyretail Molly gets her name from the distinctive shape of its tail fin. The tailfin of a Lyretail Molly Fish is fan-shaped, but its top and bottom contain long rays that make it look like the fish has a forked tail.
Care Difficulty
Care for lyretail mollies is very easy. Their basic needs are easy to satisfy. Everything from the simple setup of a tank to the ease with which waste can be removed is simple to care for.
Temperament
The lyretail is a lovely and gentle fish found in most aquariums. Compared to male bettas, they can live with many other species. Mollies are also not a very aggressive species. Even so, they can be aggressive in certain situations.
Fish Size
If you feed your lyretail mollies well, they should grow quickly. Most of the time, female mollies are bigger than males. As females can get as tall as 5 inches, and males as tall as 3 inches.
Food & Diet
Lyretails are omnivores, meaning they eat algae, small animals, and plant matter. You should also provide the same food variety in home aquariums. You can choose from flake food and different kinds of vegetables, such as medallions, shelled peas, zucchini medallions, and cucumber medallions. Vegetables are also a staple of mollies’ diets, as plants make up the bulk of their plant-based nutrition.
Water Condition
Lyretail mollies need a tank that is 72–82°F, has a pH of 7-8 and has hard water.
Tank Mates
Lyretail mollies are schooling fish, which means they like to stay together. But some aquarists prefer to keep them in tanks with only one kind of fish. This is because mollies have a tendency to nibble on fish fins, making them a poor choice for long-finned species. Mollies can live with Platies, Guppies, Tetras, Swordtails, Gourami Fish, and Pleco Catfish, among other fish.
Female Molly Fish Appearance
Molly fish reach sexual maturity between the ages of 2 and 3. You can use this data to set up a breeding program for Mollys or just keep things in check in the tank.
Key identifiers of a female Molly are listed below.
1. Color
Because female mollies have more subdued color schemes, male mollies use their more vibrant color variants to entice female mollies to mate.
2. Size & Shape
Female mollies typically reach maturity at a bigger size than their male counterparts. Females can grow to a maximum of 5 inches in length, while males average between 2.5 and 3.5 inches.
3. Dorsal Fin
The dorsal fin of female mollies is shorter than that of males. The larger dorsal fins of males are another attractive feature that usually helps in luring females for mating.
4. Anal Fin
Anal Fin is the most specific portion used to distinguish the gender, while other traits may change from species to species. The current underbelly, known as the Anal Fin, can be found in front of the tail. The anal fin of females is more triangular in shape and shorter than that of males.
5. Behavior
Women tend to be calmer and less attention-seeking than men. Except for those latter few weeks of pregnancy when they start to get irritable.
Choosing & Caring For Different Types of Molly Fish
One of the most prevalent types of freshwater fish is the molly fish. Their attractiveness and low maintenance requirements make them ideal for a home aquarium. In contrast, a fish market will have hundreds of molly fish. Trying to figure out which of those varieties is best for your aquarium can be very frustrating. So, in this article, we’ll discuss the 10 most well-liked molly fish.
This list is mainly based on how each type of molly looks and how popular it is.
Balloon Belly Molly
The balloon belly molly is one of the most common aquarium fish. It is famous mostly for how it looks. Because of its round stomach, this molly is commonly referred to as a balloon belly. The variety of colors available makes this item quite desirable. Pick whichever one appeals to you the most. Balloon belly mollies, especially the yellow kind, are highly sought after by aquarists.
Black Molly
As its other name, “common Black Molly,” suggests, the Black Molly is a tough fish that even novice fishkeepers can manage. It does best in tanks larger than 30 gallons and in water between 68 and 82 degrees Fahrenheit. Black Molly prefers a pH level between 7 and 7.8. The Black Molly is a nonaggressive species that mature at roughly 3 inches in length.
Black Sailfin Molly
It’s a calm species; however, they won’t be safe in a tank containing fin-nippers. The Black Sailfin Molly is a resilient breed that is perfect for beginners and can grow to a maximum of four inches in length. They are happy in a 30-gallon tank and enjoy having plenty of space to roam around in, despite being slightly larger in size.
Black Lyretail Molly
This is one of the largest varieties of Molly, maturing to a length of around five inches, and it requires minimal maintenance. Because of its docile nature, this fish does best when kept in tanks alongside others of a similar size. The Black Lyretail Molly is a hardy species. As long as the pH is between 7 and 8, it can thrive in a variety of environments.
Creamsicle Sailfin Lyretail Molly
This fish is a calm fish with big orange fins that doesn’t mind sharing the tank with other fish. This kind is perfect for new fish keepers because it has a pleasant appearance and can tolerate a wide range of water conditions.
Dalmatian Molly
The Dalmation Molly is another breed that does well for beginners. It is tolerant of a wide range of temperatures and may survive for extended periods of time in water that is slightly acidic or basic. The optimal range for water pH is between 7 and 7.8. The Dalmatian Molly prefers aquariums of at least 30 gallons in volume, and it can reach a length of about five inches.
Dalmation Lyretail Molly
When compared to a conventional Dalmatian Molly, this breed is smaller (often reaching just about three inches in height) and more albino in appearance (having fewer and smaller black spots). They can survive in an aquarium with a volume of at least 30 gallons and are thus ideal for newcomers. They’re generally docile, like many fish species, and only react violently when they feel threatened.
Gold Doubloon Molly
The Gold Doubloon Molly is easily identifiable thanks to its striking yellow and black color palette. Because of its short fins, it needs a large tank (at least 30 gallons) in which to swim. It is a resilient fish that thrives in a wide temperature range and can reach a length of five inches.
Golden Sailfin Molly
Bright and colorful, the Golden Sailfin Molly thrives in aquariums with hard water. One of the largest mollies, at 6 inches in length, golden mollies are as flashy as their name suggests. They are a resilient breed that can handle fluctuations in temperature, but they do need a tank larger than 30 gallons, so they have room to swim around.
Harlequin Sailfin Molly
The Harlequin Sailfin Molly, with its black and white body and many gold speckles, is a very beautiful fish. It can grow to be as long as six inches, and it’s a calm fish that gets along well with others. It thrives in water temperatures ranging from 68 to 82 degrees Fahrenheit.
What Do Molly Fish Look Like
Typically, the common molly is what comes to mind when someone mentions molly fish. Although there are many distinct species, most have the standard molly’s general body type and general appearance. The bodies of these fish are flat, and their heads are triangular. The body is broad in the middle and narrows toward the head. The tail, which is fan-shaped, is attached to a slightly narrower body.
FAQ
How Many Species Of Molly Fish Are There
Despite the fact that there are more than 40 recognized species of mollies, the common misconception is that they are all members of only one. There is a wide range of options in terms of aesthetics (color, pattern, and form) to choose from. Most species are mellow enough to coexist peacefully with a wide variety of common community fish.
What Is The Most Common Molly Fish
Black Sailfin Mollies are a melanism-stricken subspecies of the more common Sailfin Molly. As one of the easiest to care for and most visually pleasing live-bearing fish options, this is a popular choice for new aquarium owners.
What Is The Smallest Molly Fish
Dwarf molly fish resemble shortfin molly fish but are much smaller at a maximum length of just 2 inches. The average length of a female dwarf molly fish is about 1.5 inches, while the males average hair over an inch in length.
Recap
Fortunately, there is a plethora of amazing Molly fish available. The majority of species are easy to maintain and suitable for beginners. These robust fish are accustomed to variable water conditions and greater salinities in environments. Some species are more sensitive to tank conditions and require a more spacious enclosure. Some may be a little bit more aggressive or rowdy.
Understanding the characteristics of each species will make caring for them a rich and satisfying experience.