Black Molly Fish: Types, Diet & Breeding (Beginner’s Guide)

Are you looking to add a unique and eye-catching fish species to your freshwater aquarium? Black molly fish might be the right choice for you.

They are active and colorful, reaching up to five inches in length when they mature.

With their vibrant colors, these versatile shoaling fish can fit into almost any tank environment.

Not only do they provide beauty and energy – but once you learn how easy it is to take care of molly fish, this species may become a favorite among new and old fish keepers!

black mollies fish

In this molly fish black breeding guide, we’ll help you through all the basics about Black Mollies Fish, from molly fish types and diet requirements to breeding & black molly diseases and general mollies fish care for keeping them healthy & happy in your home aquarium.

Are Black Mollies Freshwater Fish?

Yes, Black Mollies are freshwater fish that can be found in rivers, lakes, and ponds all over the world.

These tropical fish, native to central and South America, is a valid symbol of aquatic resilience.

They typically prefer habitats with soft, slightly acidic water and plenty of vegetation, though they will also tolerate more neutral or brackish waters.

Do Black Mollies Clean the Tank?

Black molly fish are known to be very active, making them well-suited for aquariums with plenty of room to swim and explore.

In addition to their energy, Black Molly are also known for being incredibly clean – which means that they will help clean the molly tank, removing uneaten food and fish waste from the water.

My aquarium is clean, thanks to my mollies, who diligently work away at the algae all day!

What Size Tank Do Black Mollies Need?

Black mollies require a minimum tank size of 20 gallons. They are very active swimmers and will appreciate plenty of swimming space.

They should also be provided with plenty of live plants, as they like to hide among the leaves.

If you’re looking for a larger tank, it is recommended that you allow 1 gallon of water volume per inch of fish.

Pregnant dalmatian molly

So, a 20-gallon tank would comfortably hold up to twenty 2-inch-long black sailfin molly fish.

Black Mollies are an excellent choice for anyone looking to add vibrant colors and energy to their freshwater aquarium.

They are an easy-to-care-for species that will make any tank look great!

Are you looking for more information on Black Mollies? Check out this helpful resource to learn about caring for black molly fish.

How Long Do Black Molly Fish Live?

Most Molly fish live for about three years in captivity. However, there have been reports of some Mollies living for as long as six years.

Mollies are very hardy fish and can tolerate many water conditions. They should be kept in an aquarium with ample aquatic plants and other hiding places and fed a diet high in plant material.

How Big Do Black Mollies Get? (Black Molly Fish Size)

How big do mollies get? Black Mollies can grow up to 3½, and adult fish can grow to a maximum of 6 inches long, but usually, they are smaller. 

They are a popular fish because they do well in most community black molly tanks and are very hardy.

Because black mollies are so active and need plenty of room to swim, it is recommended that you provide them with at least a 20-gallon molly tank.

Remember to keep a close eye on the molly population in your aquarium salt water – if you have too many fish, they may begin to crowd and stress each other out.

Types of Black Molly Fish:

When it comes to fish, there are so many different molly fish types that it can be hard to track them all. 

It is hard to remember the names and characteristics of all the different types of molly fish, but it’s also tough to know which ones are best for your home aquarium.

Get acquainted with the incredible variety of Molly Fish! Discover a range of beautiful aquatic breeds, and uncover their fascinating qualities.

Orange and Black Molly Fish

The orange and black molly fish is a unique, vibrant species that is sure to make a splash in any aquarium.

These beautiful fish are known for their bright orange and black coloring, sure to captivate any fish enthusiast.

Orange and black mollies are prevalent species, requiring a minimum tank size of 20 gallons.

They should be kept in an aquarium with plenty of plants and other hiding places and should be fed a varied diet that includes live food and high-quality freeze-dried and flake foods.

Black and Yellow Molly Fish

The black and yellow molly fish is an eye-catching, striped breed that can add color to any tank. These beautiful yellow and black molly fish come in a striking yellow and black pattern, which will grab any aquarium owner’s attention.

Black and yellow mollies need a minimum tank size of 20 gallons, and they should be fed a varied diet that includes live food and high-quality freeze-dried and flake foods.

Balloon Black Molly Fish

The balloon black molly fish is a perfect choice if you’re looking for a larger molly tank. These amazing and unique fish get their name from their balloon-like body shape – their bodies are round and plump, which makes them stand out from other fish.

Black and Gold Molly Fish

Another beautiful and colorful type of black molly fish is the black and gold molly. This striking breed comes in a unique golden color with black markings, which makes it a must-have for any aquarium owner.

Black and gold mollies need a minimum tank size of 20 gallons and should be kept in an aquarium with plenty of aquatic plants and other hiding spaces.

They should be fed a black molly diet high in plant material and a variety of other foods, such as live food and high-quality freeze-dried and flake foods.

Are you interested in adding some beautiful black mollies to your aquarium? Whether you’re looking for a striking orange and black breed or a larger balloon-shaped fish, there is sure to be a black molly that is perfect for your tank.​

How Much Are Black Molly Fish Price?

The price of black molly fish can vary depending on several factors, including the black molly size and type.

Generally speaking, black mollies are relatively affordable, with small fish typically costing around $5-10 and more prominent, more mature specimens costing up to $20 or even more.

If you’re looking to purchase black molly, it’s essential to research ahead of time and compare prices from various retailers.

This will help you find the best deal on beautiful black molly that will surely be a great addition to your aquarium.

Where to Buy Black Molly Fish?

There are several places to buy black molly fish, including pet stores, online aquarium retailers, and specialized fish breeders.

When shopping for black mollies, choosing a reputable retailer can provide you with high-quality fish that are healthy and well-cared for.

Some good options include local pet stores, online aquarium retailers such as Amazon or Petco, and specialty fish breeders.

No matter where you buy black mollies, be sure to do your research ahead of time and carefully read reviews from other aquarium owners.

This will help ensure you find the best fish for your tank!

What Do Black Molly Fish Eat? (Black Molly Fish Food)

Black Mollies are omnivores and generally eat a wide variety of fish foods in their natural habitats, including insects, algae, plant matter, and other small invertebrates.

In the aquarium, they tend to thrive on a diet high in plant-based foods like shrimp pellets or algae wafers.

However, they will also enjoy regular feedings of live or frozen foods like baby brine shrimp or bloodworms.

For the best results, it’s generally recommended to feed your Black Mollies a varied diet and supplement their diet with aquatic floating plants or live foods when possible.

Do Black Molly Fish Need Light?

In general, black molly fish do not require a lot of light in their tank.

However, if you are trying to encourage the growth of live plants or algae in the aquarium, providing some additional light and a canister filter may help.

While most black mollies fish will do fine without a light in their tank, it is always a good idea to research your fish’s needs and ensure they are getting all the care and attention they need.

If you have any other queries about the care for molly fish or maintenance of black molly tank, be sure to speak with an experienced aquarium or fish expert who can help you create the best possible conditions for your black mollies.

Are Black Molly Fish Aggressive?

Black Mollies are attractive and easy to care for community fish, but black molly fish care must be taken in tank populations.

If too many males occupy the same space, they can become territorial, leading to aggression, while lone females may find themselves overexerted by attention from their male counterparts.

Can Black Mollies Live with Betta Fish?

Black Mollies are not good fish tank mates for an aquarium with Betta Fish.

While some aquarists have reported success adding a single male Betta to a community tank with Black Mollies, this can be challenging due to the territorial nature of both fish species.

For best results, it is generally recommended to keep Black Mollies in the same tank

 or with other tank mates, community fish are more compatible with their needs and temperament.

Black Molly Fish Breeding

Black mollies (Poecilia sphenops) are one of the most popular fish kept in home aquariums and are relatively easy to breed.

The key to getting black mollies to breed is to provide them with a calm, stress-free environment and plenty of places to hide.

In addition, it’s essential to keep the water temperature at around 80 degrees Fahrenheit and ensure the pH level is between 7.5 and 8.0.

Black mollies usually begin breeding within a week or so after being introduced into a molly fish breeding tank.

After an elaborate courtship, the male and female Molly fish engage in a unique form of fertilization.

The male black mollies impregnate females using their specialized gonopodium, which releases sperm into her duct for successful reproduction.

How Often Do Black Mollies Reproduce?

Mollies reach sexual maturity and continue to reproduce for an impressive 2-2.5 years, breeding often – around every 30 days!

With such a prolific reproductive rate, you can imagine the large number of offspring this molly types produces in its lifetime.

What Is the Fastest Way to Breed Mollies?

Breeding mollies can be a difficult and time-consuming process. With the proper knowledge, tools, and caring for molly fish, breeding mollies can be an effortless task.

How to Breed Black Molly Fish? In this video, you will find everything you need to know about breeding mollies quickly and easily. You will also learn how to care for your new molly fish brood properly.

How to Identify Pregnant Black Molly Fish?

To identify a pregnant black molly fish, look for a large, dark gravid spot(thick-bellied) female that is swollen with eggs. She will be darker in color than the other females in her group and may have a greenish hue.

You can also look for changes in the shape of her body; she will be much more pronounced around the belly and may have an increased dorsal fin size.

If you are unsure whether your Poecilia latipinna sailfin molly fish is pregnant, watch her closely for two to three weeks.

If she starts depositing eggs on the tank bottom or shows other signs of being ready to give birth, she is most likely pregnant.

How Many Babies Can a Black Molly Have?

Molly is a livebearer fish, which means that they give birth to live young. Females can have between 40 and 100 fries at a time.

The number of fries she has will depend on her age, health, and the size of the male she is mating.

Young females typically have more fry than older females, and larger male mollies typically produce more fry than smaller males.

Fry are born small and require a lot of care to survive. They need to be fed a special diet designed for baby fish, and they need to be kept in clean water at all times.

If you cannot provide this level of care, it is best to rehome the fry in an aquarium with other mollies or similar-sized community fish.

How Long Is a Black Molly Fish Pregnant?

How long do black mollies stay pregnant? The gestation period for a black molly fish is 45 to 60 days. 

After fertilizing the eggs, the female will deposit them in a sheltered area and typically stays close by to guard them.

The fry (newly hatched fish) will be utterly independent once they emerge from the eggs.

It is essential to provide them with plenty of food and clean water during this critical period, as they are highly vulnerable to infection and illness.

Commonly Asked Questions about Black Mollies Fish (FAQ)

How Much to Feed Black Molly Fish?

How much do you feed black molly fish? In general, it is recommended that you feed your mollies high-quality flake food one to three times per day.

How Do Black Molly Fish Sleep?

Do black mollies sleep? Mollies often rest at the tank’s surface at night but do not usually sleep for long periods. If you notice that your mollies are not swimming or feeding, it could be a sign that they are sleeping, or it could be a sign that they are sick.

Why Did My Black Molly Fish Die?

There are some possible reasons why your molly fish may have died. Some common causes include infection, stress, poor water parameters, or old age. If you suspect that your molly has died from one of these causes, it is essential to take steps to prevent similar deaths in the future.

How Do Black Mollies Fish Mate?

The male black molly fish typically initiates mating by chasing and nipping at the female. Mating takes place in a side-by-side position and can last for several hours. Once the eggs have been fertilized, the female will store them inside her body or lay them on the tank bottom. canister filter

What Are the Best Tank Conditions for Black Molly Fish?

Black molly require a spacious, well-filtered tank that contains plenty of hiding places and java ferns. The temperature should be 76 to 82 degrees Fahrenheit, while alkalinity should be between 10 and 20 pH.

Are There Any Differences between Male and Female Black Mollies?

Male and female black mollies look very similar, with the main difference being that females are usually a little larger than males. In addition, females typically have a dark patch in the middle of their belly, which is used to store the fry after mating. Males do not have this marking.

How Do Black Molly Fish Give Birth?

Female black molly fish give birth to live young, called fry. After the eggs have been fertilized, the female will either deposit them in a sheltered area of the tank or carry them inside her body until they are ready to be born. Once she gives birth, the fry will be wholly independent and require special care to survive.

Do Black Mollies Have Babies?

Yes, black mollies are known to reproduce relatively quickly. They typically breed in the spring, but they may also lay eggs at other times of the year.


Overall, black molly fish is an excellent option for beginner aquarium owners. They are relatively low-maintenance and can live in various tank setups. Regarding diet, black mollies are not picky eaters and will accept most commercial fish food. If you’re thinking about breeding black mollies, you must have both male and female fish in your tank. Lastly, keep an eye on your black molly’s fins, as they are susceptible to anal fin rot. With the proper black molly care, your black molly can thrive in your home aquarium for years to come!

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About Me

I am the founder of, a devoted wife and mother, and an avid fish enthusiast. My aim is to assist fellow fish lovers worldwide in understanding how to properly care for and breed their pet fish.

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