Molly fish - Mollies

Molly Fish Care, Types, Tank Setup, Food, Breeding, etc.

When we discuss about freshwater fishes, then nobody forget to enlist Molly fish.

Molly fish is the most common fish that I am sure, everyone has seen once at some point. Mollies are easy to maintain, care, and beautiful in looks.

Even a beginner can start fish keeping hobby with these non-aggressive fishes. They are active and available in all shapes and colors.

Mollies will add color and variety to your tank. They are also famous for their unique behavior and personality. Watching them swim will help reduce anxiety and keep engaged to them.

Here, we are going to discuss everything about Mollies, from their behavior to how to breed them. But before that, take a brief look at the table.

Category Rating
Family Poeciliidae
Temperament Peaceful
Diet Omnivores
Color Form Various
Size Up to 4.5 inches
Lifespan Up to 5 years
Care Level Easy
Tank Set-Up Freshwater, planted tank
Compatibility Peaceful community aquarium
Minimum Tank Size 10 gallons

Molly Fish Overview

Molly fish - Mollies
Balloon Molly Fishes

Molly, from family Poeciliidaae, is a native of America and most commonly found fish. They belong to the Poecilia genus with 40 different species. Except for Endler livebearer, all 39 are Mollies.

They are hardy and easy to breed. They are livebearers like Guppies, that is, they give birth to their young ones directly into the water.

They are non-aggressive so it’s easy to keep them in the community tank. You can even start your fish keeping hobby with a group of Mollies as they are not that costly also. You can buy them in $2-$4 but the rare species of Molly can cost more. They are readily available in all the pet stores.

If kept in healthy and with constant water conditions, they can live up to 5 years.

Molly Fish Behavior

They are famous for their peaceful behaviors but they can get aggressive if kept in an overcrowded tank or with aggressive mates. Make sure there is ample space for them or other fishes to swim and the temperament of other fish matches with theirs.

Mollies are social and like to be in a group but the shoal should have more females than males. The males can stress and harass the females.

Once you see the differences in their personalities, you will automatically find yourself attached to them.

Molly Fish Types and Appearances

Molly fish comes in varieties and they share some of their characteristics with Common Molly (Poecilia sphenops). Still, they differ in color, size, and shapes.

The common Molly can be easily recognized through its flat body with a wide abdomen area. Some dorsal fins are like causal fins in the shape of the fan while others flatter against the body.

The anal fin of the female Molly is spread into fans whereas that of males is pointy. The fins can be either transparent or colorful.

The females are bigger in size usually 4-5 inches whereas the males are shorter usually 3 inches.

As we discussed earlier, there are different types of Mollies. The following are the most commonly found and famous Molly –

Lyretail Molly Fish

Lyretail molly fish

This specie is easily recognized through its caudal fin. It has a narrow top and bottom that drags behind its body.

Sailfin Molly Fish

Sailfin molly fish

This specie of Molly is recognized through their large dorsal fins that start from behind the head and ends at the caudal fin. They come in many colors and patterns.

Black Molly Fish

Black molly fish

This specie is similar to Common Molly except for its body which is covered in black color.

Other famous species of Molly include Balloon, White, Red, Orange, and Dalmatian.

Balloon Molly Fish

Molly fish - Mollies

White Siliver Molly Fish

White silver molly fish

Red Molly Fish

Red molly fish

Orange Molly Fish

Orange molly fish

Dalmatian Molly Fish

Dalmatian molly fish

Molly Fish Tank Setup

Molly fish tank setup

Habitat and tank conditions

The Mollies are hardy as their habitat varies in the wild. They have developed a tolerance for high hydrogen sulfide levels and brackish water. They are usually found in rivers and streams across South and North America.

The tank conditions suitable for Mollies can be understood through the below table –

Conditions Parameters
Temperature 72-78°F
pH 6.7 to 8.5
Hardness 20-30 KH

You have to maintain the same water conditions as their natural habitat. The best part, you don’t have to maintain different conditions for different species of Molly.

They are habitual of the tropical climate. It is important to maintain the temperature of the water and provide ample lighting in their tank. You can place a thermometer at one corner of the tank and a heater for maintaining temperature.

They live in streams and rivers so, make sure there is a little flow in water too. It can be easily achieved by the filter outlet itself. You can choose any plant and substrate of your choice. But we will recommend you to use tall plants as they are middle swimmers. They also need a lot of hiding space for shelter and breeding.

For substrate use the fine-grained one as they will help you hold the plants in the water. Also, use rocks, caves, and crevices for decoration. It also helps the fish to hide if other fish causes stress or harass them.

If you are planning to have only Mollies in the tank then you can add a little brackish water as well. But, in a community tank, it can affect the health of other fishes.

What is the minimum tank size for molly?

A single Common Molly and other specie of its size need 10-gallon capacity aquarium. And you can add 3 gallons per Molly you add in the tank. It will give them enough space to swim without feeling overcrowded.

In contrast, large species like Sailfins need at least 30 gallons tank.

Molly Tank Mates

We have already learned everything about the behavior of Molly. They are peaceful and can be easily kept with other non-aggressive fishes.

The best molly fish tank mates are – Rosy Barbs, Cherry Barbs, Danios, Zebra Loaches, Harlequin Rasbora, Corydoras Catfish, Yo-yo Loaches, Tetras, Platies, and Dwarf Gourami, etc.

A freshwater cherry barb fish
A freshwater cherry barb fish

Other non-fish mates will live happily with them, for example, shrimp and snails. They will be mostly unnoticed.

Never put Cichlids with Mollies. Cichlids are aggressive, they will eat or harass your Mollies. Any fish that are bigger or non-aggressive should be avoided at any cost. The only specie of Cichlids that can live peacefully with them is Angelfish.

Mollies are famous for their social behavior. They usually stay in a group while in the wild. So, keeping mollies in a group is the best way to maintain variety and make the aquarium look colorful.

While making a group, make sure it is either all females or their number is more than males. The males are notorious for harassing them.

What Do Mollies Eat? 

Mollies are habitual of living in different habitats so feeding them won’t take much effort from you. Mollies are omnivores so they will eat whatever you feed them. In the wild, they usually feed on invertebrates and algae or plants.

What to feed molly fish?

Algae constitute the base of the diet of Molly. Still, feed them other things as well to maintain variety in diet and avoid nutrient deficiency. You can also feed them vegetables like spinach, lettuce, and zucchini by breaking or mashing them in small pieces.

You can also use premade food like flakes and pellets as a supplement with other foods. They will maintain the nutrition level in their body and keep them healthy. In a non-vegetarian diet, you can include both live or frozen food like brine shrimp, bloodworms, etc.

Feeding twice a day is enough but make sure they are neither underfed nor overfed. Both conditions are harmful to them. Feed only the amount they can finish in two minutes. It’s a universal rule for feeding any small fish like Mollies.

Molly Fish Care Guide

Mollies are easily adaptable to different natural environments and conditions. The reason is their presence in a wide range of habitat. The first and foremost thing to keep in mind is consistent water conditions and a clean tank.

You should know how to clean the tank effectively. Also, the level of nitrites and ammonia should be minimum.

The poor water conditions and unclean tank can give rise to many diseases. Molly disease, also livebearer disease or shimmies, is a common condition found in Mollies. The common sign for this condition mainly includes less activity in them. Like shimmying or wiggling in one place.

If you see this, check the water conditions and correct the issues. Once the conditions are back to normal, the health of the fish will also improve gradually.

Apart from this condition, they can also get itch or fungus infection. It is quite common in freshwater fishes. The diseases can easily be cured if spotted on time. So always observe their activities and if you see anything strange consult a doctor.

Clean the tank in every one or two weeks and only 25% of water. It will keep toxins to the lower level and maintain the water conditions.

Breeding Mollies

Mollies are one of the species of fish that are easy to breed as they mate regularly.

They are livebearers and the eggs are produced inside their body. When the time comes they give birth to their young ones in the water directly.

They usually become sexually mature in six months for females and twelve months for males. If you are planning for the breeding of Mollies, make sure the water conditions are constant and avoid making any changes or adding any new mate to the tank.

Breeding mollies

How to breed mollies?

The males attract female Molly from courting rituals. The females choose the male who has flowing majestic fins and brightest appearance. Once the female allows to mate, the male fertilizes the egg. After the fertilization, you can put female to another tank as the activity of male can distress pregnancy.

It takes almost 35-45 days for eggs to hatch. A healthy and big female Molly can give birth to 100 fries at once. Make sure the water conditions of the breeding tank are similar to the main tank. As the inconsistent conditions can cause stress and result in miscarriage.

After the fries come out of their mother, you should put the female back into the main tank. It is important as she can eat up her fries.

The young ones need care and a lot of protein. You can feed them flakes after smashing or breaking them in smaller pieces. Once they reach maturity, you can put them back in the main tank and feed the same food as adults.

FAQs on breeding mollies

Q: How to spot pregnancy in female Molly?

Ans: The abdomen area of the Molly looks swollen and their color changes a little when they are pregnant. With time, their body gets bigger. When you spot pregnancy, separate the female Molly from the main tank.

Q: What another alternative I can use instead of having a breeding tank?

Ans: You can use the breeding net. It will keep the female separate from the rest of the fishes. After birth, the fries can easily swim out of the holes of the net leaving their parents inside.

Should You Keep Molly Fish?

Mollies are non-aggressive freshwater fishes. They are easy to take care of and don’t need high maintenance and even costs less than any other fish. They are easy to breed as well.

They will add beauty and variety to your tank. These reasons are enough to make them the perfect choice for a beginner to start the fish keeping hobby. Right water conditions, right tank mates, and cleanliness are all they need to be healthy and happy.

They are omnivores so you can easily add a variety of food in their diet.

What are the characteristics that you like most about them? Are you planning to have them? Let us know.