Molly Overview:

Mollies are fresh water species & they are from the Poeciliidae family. Molly is an American native fish, but they have different habitat.

Mollies are livebearers which mean they don’t lay eggs. Their eggs are in their bodies until they hatch & fries are born. Fries go out of the mother body.

If mollies are kept in better aquarium conditions, they can live up to 5 years.

Mollies are sold for $2 to $4 per one fish, but there are also special mollies that are a bit expensive.

Molly is usually found in Mexico. They love to live in fresh water streams but live in marine water too.

Common size of male molly is 3 inches, & size of female molly is 4.5 inches.

It is a common fish & many aquarists keep them in aquariums. Mollies are also known as beginners fish because they are hardy & do not need high care.

Mollies are active & live in community; they show peaceful nature when kept with other fish. Molly is a lovely fish & you can get them for a cheap price. Almost every fish store has mollies due to their popularity.

Mollies are available in a number of colors & varieties. There are many from which you can select & you can find the one you love the most.


Category of Molly


Level of Care




Available Colors



Can live up to 5 years


Omnivores, can eat vegetables & live food



Min. Aquarium Size

10 gallons

Aquarium Setup

Freshwater, Aquarium with Plants


Molly Behavior:

Mollies are peaceful & good community fish but they can be aggressive sometimes when there are many in a tank or when their mates are aggressive. Make sure you have enough space in your aquarium, & they have peaceful mates. They are active & love to swim in groups.

A number of mollies are available. They have diverse colors & patterns, but they can also vary in sizes & shapes.

Common molly has a flattened body. Mollies are tall in the center & they are narrow toward a point at the mouth. Caudal fin is located at the other end of the fish, which is like a large fan that vary in colors.

Reproduction of mollies is simple. Anal fin of female molly is like a fan but male’s anal fin is a pointer. Female molly is larger, that can be up to 4.5 inches. Male molly can reach up to 3 inches.

Pregnant female molly is larger in size. They have swollen bellies that are bigger than other female mollies.

Image Credit: MrFishKeeper.Com

Molly Habitat and Aquarium Conditions:

Habitat of this fish can be different. They can live in diverse water conditions, such as it can tolerate brackish water & greater level of hydrogen sulfide.

Mollies live in shallow parts of rivers & streams in America. Mollies use plant for hiding but can use them for reproduction too.

Mollies need warm slow moving water. They like living in slightly alkaline water.


Molly Aquarium Setup:

Mollies do not need difficult setup because they are beginners fish & can live in normal aquarium conditions.

They love planted aquariums & you can put rocks & other structures for decoration. You can use them for the fries to hide from adult fish. Even females can use them to hide from males when they are harassing them.

Mollies live in aquarium with water temperature between 72 to 78 Degree Fahrenheit. Ensure pH of water is from 6.7 to 8.5, & water hardness is kept from 20 to 30 KH.

Some aquarists like a little brackish water for these fish. The notable advantages are not known yet, but you can’t keep many other fish in the community tank with brackish water, so do not add brackish water to your tank.

Use normal lights in your tank. There is no need for special equipment. Mollies like slow moving water which can be achieved through the outlet of aquarium filter.

Mollies require at least 10 gallons of water. You can keep up to 4 mollies in 10-gallon aquarium but if you are keeping more, then we would recommend a 30-gallon aquarium.

Adding another molly will require about 3 gallons of water for best conditions.


Molly Tank Mates:

Mollies are peaceful community fish & they do not hurt other fish, so they have no problem with other peaceful fish in tank.

You can keep other peaceful fish with mollies such as Cherry Barbs, Corydoras Catfish, Dwarf Gourami, Danios, Platies, Rosy Barbs, Zebra Loaches, Tetras & Harlequin Rasbora.

You can choose from a number of available choices including other small peaceful fish that love to live in community.

Do not add large aggressive fish to aquarium. They may eat mollies, & other aggressive fish may harass them till death.

You can add snails & shrimp in molly tank & there are many other fish that can be chosen.


Molly Diet:

Mollies are omnivores & they eat a number of foods. They like to eat small invertebrates in the wild, but their main food is plants & algae. You can offer them a number of diets when keeping them in tank.

Offer them algae because they love to eat it, they scrape it from surfaces using their lips. Feed them vegetables. They love to eat flakes & pellets.

Feed them live & frozen foods that contain high protein.

Offer them little foods 2 times a day. It helps them digest well. Offer them as much food as they can eat within 2 minutes.


Molly Care Guide:

Mollies are hardy & they can adjust to your tank conditions. You can keep them in clean aquarium. Make sure you change water regularly. Monitor conditions of tank water & ensure ammonia & nitrites are under control.

They may get an illness known as ‘molly disease’. This is not an illness but mollies get it due to bad water conditions. Fish that are affected with this disease won’t swim well, & would stay at one spot. Make sure you monitor your water conditions in such situation, when water conditions are back to normal then you will see better activity from affected fish.

Mollies might get other illnesses too including ich & velvet. Make sure you give time to monitor your fish every day for the signs of illness. Common diseases have sign such as loss of appetite, less activity, spots on fish, wounds & changes in color of molly. Clean your aquarium & changing food can help lower chances of illness in mollies. If you have problems with your mollies, then you can treat those diseases with medicines.


Breeding Molly:

Mollies do not lay eggs & their eggs form in their bodies & when they hatch, they release fries in water. Such phenomena make mollies live bearers & it is very simple to breed them in aquarium & they mate easily.

Make sure you keep better water conditions in aquarium in order to breed mollies. Ensure clean aquarium water & raise the water temperature that helps in mating. Do not increase it beyond 78 Degree Fahrenheit. When female molly is ready for mating then she will let male molly to fertilize her eggs.

When eggs are fertilized, then female take around 35 to 45 days to release the fries. Bigger mollies can give birth to even 100 fries.

Make a separate tank for fries or adults will eat them. One of the choice is to set up a breeder box & put pregnant mollies in them before they release fries, this way only babies will leave the box through little holes but adults won’t be able to cross it.

Offer fries diet including broken flakes until they grow large & start eating regular foods. Mix young with adult mollies once they start eating the same food of adult.

Post a Comment

Previous Post Next Post