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8 Different Types of Molly Fish

A collage of different types of Molly fish.

The molly is a common fish found in many aquariums and the fish tanks at many retailers that sell aquarium fish. Mollies are not one single type of fish. There are many species and types of mollies, including several that are favorite additions to aquariums. 

The bodies of the fish are often striking in appearance. Fishkeeping World divides the most popular types of mollies into three major categories, including the natural molly fish, the selectively-bred sailfin molly, and the selectively-bred lyretail molly. 

Do not purchase a couple of mollies and drop them in your aquarium. How do you care for them? What type of tank do you need for your mollies? How long do molly fish live in the domesticated aquarium setting? Can you put mollies in the aquarium with your other fish? 

Discover what you need to know before adding this fun, peaceful fish to your home or office aquarium. 

1. Common Black Molly

Common black molly eating aquatic weeds.

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Black mollies ( Poecilia Sphenops) have a serious case of melanism. Melanism is a condition that results in an unusual darkening of body tissue. It is caused by over production of melanin.

 The black molly has a velvety black coloring that proves striking in an aquarium with other species or types of fishSealife Planet explains that the black molly is referred to as the “common molly.” 

Black mollies are indigenous to the Southern United States, Mexico, Central America and South America. 

Type of Aquarium Needed 

Black mollies are freshwater fish. They are adaptable to a salty water environment. You need a specific type of home for your black mollies.  

Some sources indicate that you need at least a 10-gallon aquarium. Most sources recommend at least a 20-gallon aquarium. The size of the aquarium depends on how many fish you have, including how many mollies you have in a single aquarium. 

Keep the water temperature between 72 and 82-degrees Fahrenheit. Keep the pH between 7.5 and 8.5. Make sure that you have an efficient filtration system.  

Caring for Black Mollies 

Black mollies are a favorite aquarium fish because of their peaceful nature and because they are easy to care for as aquarium fish. They like to roam, especially near the top and middle of the aquarium. Give them plenty of room for their roaming habits. 

The black molly is a sociable fish, so it gets along with many other aquarium fish. Do not place black mollies in an aquarium with aggressive fish. Doing so will result in them becoming stressed and likely not thriving to their best ability. 

Consider other usually calm fish that live peacefully with black mollies, such as swordtails, tetras, or zebra fish. Do not purchase a single pair of black mollies. You need a minimum of two to three females for every male.  

Black mollies breed easily, which adds more of them to your aquarium. Remove the pregnant female from the aquarium so that she does not become stressed by aggressive males. Take the babies and place them in a separate tank until they are large enough to avoid cannibalistic mollies. 

Lifespan 

The lifespan of black mollies is usually around three years. Some mollies survive for about five years. Prepare a healthy environment and you may increase the life of your black mollies. 

Pros 

Black mollies are docile fish that like to live harmoniously with other peaceful fish. They are relatively easy to care for as long as they are not harassed by aggressive fish.  

Cons 

Black mollies breed easily and easily give birth to dozens of baby mollies at a time. Plan for the prolific addition of black mollies to your aquarium. 

Feeding Black Mollies 

Keep plenty of live plants in the aquarium for your black mollies. They also eat vegetable flakes, brine shrimp, bloodworms, algae and algae flakes. Give them only enough food to consume in three to five minutes. 

Additional Information 

Watch your black mollies for signs of illness such as ich. It appears as white spots on the skin. Some other diseases include tail rot, which affects stressed fish. 

2. Short-Fin Molly

A white Short-Fin Molly on inside the aquarium.

Short-fin mollies are one of the mollies whose coloring appears as natural in aquarium settings as in the wild. Males appear more colorful than the duller, silver-gray females.  

It is a hardy fish that adapts well to aquariums. Give them room to roam in the home or office aquarium. 

Type of Aquarium 

Short-finned mollies like to have an aquarium with plenty of live plants. Make sure that you have other vegetation and shelter. Give them room to roam about the entire aquarium. 

Keep your mollies in a minimum of a 20-gallon aquarium. You need a water temperature between 72- and 82-degrees Fahrenheit, with a pH of 7.0 to 8.5.

Fishkeeping World stresses the need to add one teaspoon of aquarium salt to the water. It helps to prevent diseases. 

Caring for Short-finned Mollies 

Short-finned mollies like to live peacefully among other fish. Do not place them in an aquarium with aggressive fish.  

Short-finned mollies breed frequently, so make sure that you have more males in the aquarium than the number of females. Remove the young from the aquarium. 

Lifespan 

The short-finned molly grows to two to three inches. It lives for three to five years. 

Pros 

Short-finned mollies are easy to care for and acclimate easily to most aquarium settings. They are social fish, yet like to hide at times.  

Cons 

The silver-gray color does not present a colorful, striking addition to the aquarium. You may consider other species or more colorful mollies if you want an unusual fish. 

Feeding Short-finned Mollies 

Give this fish algae-based flakes, mosquito larvae, and live or freeze-dried bloodworms. Consider adding veggies to their diet. 

Additional Information 

The male is usually smaller than the female. Their native home is in shallow freshwater areas or brackish coastal waters.  

3. Dalmatian Molly

2 Dalmatian Molly on a white background.

Dalmation mollies are a great addition to aquariums. Their spotted appearance draws attention. The primary color is usually silver or white, with black and deep blue spots. 

Type of Aquarium 

Give the dalmatian molly a lot of room. Make sure that there are other dalmatian mollies in the aquarium. The schooling fish needs a minimum of a 30-gallon aquarium with a gravel substrate. 

Keep the temperature between 68 and 82 degrees. Make sure that the pH is 7.0 to 7.8. 

Care 

Dalmatian mollies are easy to care for and happiest when they have a peaceful environment. Consider adding swordtails, guppies and other peaceful fish to your aquarium. 

Lifespan 

Dalmatian mollies live three to five years. They grow to four to five inches in length. 

Feeding 

The dalmatian molly is an omnivore, but make sure that they have vegetable-based flakes, along with bloodworms and brine shrimp.  Do not overfeed. 

Pros 

The dalmatian molly adds a unique type of fish to any aquarium. The coloring and markings make it a popular fish.  

Cons 

People sometimes say that the dalmatian molly is the product of mollies breeding with other types of mollies. Know that this molly may breed with your other mollies. 

4. Balloon Belly Molly

Balloon Belly Molly on the white background.

Balloon belly mollies get their name from their distinctive shape. The fish always looks like it is overweight.  

It is a hybrid type of molly, captive-bred and has various shades of yellow, orange, black, and silvery white. 

Type of Aquarium 

Balloon belly mollies have a peaceful temperament. Make sure that your aquarium set-up maintains that peaceful environment. 

Keep the water temperature at 68-82 degrees Fahrenheit, with a pH of 7.0-7.8. Add interesting live plants to the 20 to 30-gallon aquarium. 

Care 

The balloon belly molly requires more care than some other mollies. Do not deviate from the proper aquarium and water conditions if you have this fish.  

Feed the fish at different times than other fish. This keeps them from having to compete for food. 

Lifespan 

The lifespan of this fish is 1.5 to 2 years. It does not live as long as other mollies. 

Pros 

These fish make colorful additions to your aquarium. There is a variation in the acceptable water temperature.   

Cons 

No one knows whether the balloon belly molly experiences pain because of its arched back and large belly. They may have a potentially fatal disease or a shorter life span, compared to other types of mollies. 

Feeding

The primary sources of food are plants and algae. They are omnivores, so add bloodworm and brine shrimp to their diet. They like to eat bits of lettuce, zucchini, or shelled peas.

5. Sailfin Molly

Sailfin Molly inside the aquarium.

Sailfin mollies add variety to the aquarium. The fish comes in a variety of colors.  

There are sub-species of this fish that are the result of cross-breeding in aquariums. The broad dorsal fin and other unique characteristics make the sailfin molly a popular aquarium fish. 

Type of Aquarium

Close up photo of a white Sailfin Molly.

Sailfin mollies like water temperatures similar to that of most other mollies. Keep the temperature between 68 and 82 degrees. Maintain the pH at 7.0 to 8.5.  

Sailfin mollies need a 30-gallon aquarium. Change at least 50 percent of the water each week. 

Care 

Sailfin mollies thrive in the proper setting. Do not put them in an aquarium with fish that like to bite the fins of another fish.  

Be aware that these fish crossbreed with other mollies. 

Lifespan

The sailfin molly lives up to five years. Prolong its life by keeping its environment healthy and free of aggressive fish. 

Pros 

Purchase sailfin mollies in a variety of colors to add more interest to your aquarium. The fish is easy to identify because of the sailfin on the male. 

Cons 

Some sailfin mollies do not survive five years, and may die in less than two years. 

Feeding 

Feeding sailfin mollies is an easy task. Make sure there are live plants in the aquarium. Feed them algae-based flake food, mosquito larvae, tubifex, and freeze-dried bloodworms. 

6. Yucatan Molly

Yucatan molly fish swimming inside the aquarium.

The Yucatan Molly lives in the coastal waters of the Yucatan Peninsula. Yucatan mollies are also known as giant sailfin mollies. The captive-bred Yucatan mollies have brighter colors than those that live in their wild habitat. 

They are adaptable to aquariums with the proper care. It is a sailfin molly and has a larger dorsal fin compared to other sailfin mollies. 

Aquarium Setting 

Get a larger aquarium, at least a 40-gallon tank for this larger type of molly. It grows to five to seven inches in length. 

The water temperature for Yucatan mollies needs to be between 77- and 83-degrees Fahrenheit. Keep the pH at 7.0 to 8.5. 

It is sensitive to changes in water temperature. Add a heater during colder months. 

Make sure that there are more females than males to keep the males from chasing one female. 

Care 

Yucatan mollies require someone with more expertise to care for them. 

Let Yucatan mollies gradually get accustomed to any water changes. Monitor the water temperature at all times. 

The fish is peaceful and likes to be around other peaceful fish. They are more difficult to breed compared to other mollies. 

Lifespan 

The Yucatan molly lives three to eight years. Provide larger aquariums if you have a school of Yucatan mollies. 

Pros 

Yucatan mollies are great fish for experienced aquarists. The color variations make them a good addition to an aquarium. 

Cons 

Do not plan to breed dozens of Yucatan mollies, since they are more difficult to breed than most other mollies. They are larger and longer, so they require more space. They might bully smaller fish. 

Feeding 

The Yucatan molly is an omnivore. They prefer a vegetarian diet.  

Provide live plants, vegetable flakes, and veggies such as bites of lettuce, cooked spinach or peas. Feed them an occasional treat of mosquito larvae. 

7. Platinum Lyretail Molly

Platinum Lyretail Molly inside an aquarium.

The platinum lyretail molly is a graceful fish. The solid silver-white color of the fish provides a striking contrast to the more colorful fish in your aquarium. 

Aquarium Setting 

Place your platinum lyretail mollies in an aquarium with other types of fish that do well in a saltwater environment. Keep them in a minimum of a 30-gallon aquarium. Maintain the conditions in your aquarium for this fish. Keep the temperature at 72-78 degrees Fahrenheit. 

Care 

Do not place this molly in a small aquarium. Failure to provide a larger space for this fish results in the male not growing its dorsal fin to a larger size. 

Put new lyretail mollies in the aquarium with the light off for at least four hours to allow them to acclimate to their new home.  

Keep the silver fish in an aquarium with other peaceful fish to avoid stress.  

Lifespan 

Platinum lyretail mollies live for up to five years. Keep them in the right size tank at the right temperature and provide the proper diet to maximize their lifespan. 

Pros 

The platinum lyretail molly likes a peaceful environment. They get along well with other saltwater fish. 

Cons 

They need to have salty water in their tank. They can adapt to freshwater at times. 

Feeding 

Feed this fish algae and keep live plants in the aquarium. They like tiny invertebrates, bits of zucchini and shelled peas. Aquarium Circle advises providing the same diet all the time.  

8. Creamsicle Molly

A school of Creamsicle Molly.

Add this striking orange and white fish to your aquarium for its gorgeous coloring and peaceful nature. The transparent fins provide additional detail. 

Aquarium Setting 

Keep the temperature in the aquarium containing creamsicle mollies at 72-82 degrees. Maintain the pH at 7.0 to 7.8.  

Make sure to add plenty of plants and shelter spaces in the tank for this fish.  

Care 

The creamsicle molly is easy to care for and an excellent option for fish tank beginners. It lives well with other types of mollies and different types and species of peaceful fish. 

Consider adding fish such as danios, dwarf guramis, and swordtails to aquariums with creamsicle mollies. 

Lifespan 

Creamsicle mollies are a smaller type of molly. They live for three to five years. 

Pros 

The markings of the creamsicle molly make it a nice addition to aquariums. It is okay to house them in a smaller tank. Make sure that you purchase a minimum of a 20-gallon aquarium. 

Cons 

Creamsicle mollies give birth to live babies. House pregnant females away from other fish, who will eat the swimming babies. 

Feeding 

Feed creamsicle mollies a diet of fresh plant food. Maintain live plants in the tank. Feed the fish occasional bloodworms or brine shrimp. 

Can I keep all types of mollies in the same aquarium? 

Most mollies get along well with other mollies. Make sure that you do not add sailfin mollies to an aquarium with other fish that like to nip at fins. 

Can baby mollies thrive in the tank with other fish? 

No. Keep pregnant mollies in another tank. Remove the babies immediately after birth. Mollies and other species eat live baby mollies. 

How can I prolong the life of my mollies? 

Maintain a healthy pH and keep the water temperature at the proper setting. Feed mollies the recommended diet. Keep the tank clean to minimize risk of illness. 

Sources:

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