Dalmatian Molly: Overview, Care & Tank Requirements

Dalmatian mollies are species that belong to the large mollies family. Also, they are one of the most popular fish in home aquariums. They are widely known as incredibly prolific breeders in the wild.

Caring for dalmatian molly can be quite easy. However, it may be difficult when a fish-keeper has no enough information as regards their up keeping.

If you ever wonder about how to go about caring for your dalmatian molly, this article is the right choice for you. As it contains information that will help sustain the general well-being of your fish.


Dalmatian molly belongs to the sailfin family, with a botanical name, Poecilia latipinna. Also, they are a popular hybrid color variation. The Dalmatian molly is sometimes called sailfin molly. Also, they can cope with varieties of salt levels in an aquarium. They can survive in either the saltwater aquarium or freshwater aquarium. Whereas, many home aquarists keep their fish in freshwater habitat.

However, if you will be keeping your fish in a freshwater aquarium, we recommend you add a teaspoon of aquarium salt per gallon. Also, it is better to install a good filtration system in your aquarium tank. As Dalmatian mollies have hearty appetites. The Dalmatian mollies are very suitable for a community tank, as they are compatible with other peaceful species that can thrive in hard water. However, they are known for bulling their babies, and that of other fish in the tank.

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Moreover, you can differentiate the male from female sex by their fins. As males have a larger dorsal fin and a pointed anal fin than females. While the females have a rounded anal fin. Dalmatian mollies are livebearers that require a large breeding tank. As they release many babies at birth. Adding a group of floating plants at the corners of the aquarium tank will serve as keeping space to rear the babies. Usually, female mollies produce babies a lot. Sometimes, they release fry every 60-80 days, giving birth to 40-100 fry.

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Dalmatian Molly Size

Dalmatian mollies grow up to 3 inches in length. And their young are usually about half an inch. With their body size, they are able to cope with another type of fish in a community tank. However, they nip at other fish in the tank. As their nipping is the only thing you may have to be concerned about. Meanwhile, having a large tank that can accommodate your fish, will help manage this situation. Also, fin-nipping is not a threatening act. Moreover, your fish will grow healthy, if you feed them with an adequate diet, and keep them in an appropriate water condition. Usually, female mollies are larger in size, than male Dalmatian species. Whereas female dalmatian mollies can grow up to 4.5 inches (12cm), and the males grow up to 3 inches (8cm).

In keeping dalmatian mollies together, you should ensure to put similar sizes in the same tank. Moreover, this will prevent bigger fish from bullying the smaller ones.

Dalmatian Mollies Appearance

Most wild mollies are silver, with a color touch on their fins. However, you should know that most mollies you see today are results of selective breeding. They are captured, and carefully bred to achieve a desired trait. Moreover, selective breeding has produced a variety of color, body, and fin shapes. Whereby, many varieties are results of cross-breeding sailfin and short-finned.  However, the commonly available molly color is the black molly. Whereas, Dalmatian mollies are popularly known for their silver and white speckles.

Dalmatian Molly Tank Size

It cannot be overemphasized that fish require a spacious tank for their up keeping. With big aquariums, caring for your Dalmatian molly will be an easy task. However, mollies can thrive in various environments. As they can manage in a small tank, but it largely affects their water condition. Whereas, a poor water condition is the major contribution of harm to the fish. Moreover, inappropriate water conditions could enhance the growth of microorganisms. As parasite infections cause damage to the body. And death in severe cases. A smaller water quantity will make cleaning tiring. Whereas, dirt, poop, and wasted food will easily accumulate in the tank.

Concerning the tank size, a lot of aquarists make use of 20 gallons. However, the number of fish largely determines the tank size you will be making use of. However, for dalmatian fish that are more than 3 inches in size, ensure you keep them in a minimum of 30-gallon size. Moreover, you need to consider creating space for enough oxygen in your fish tank. As they need oxygen for survival.

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Group Size: Mollies are schooling fish that need a lot of company, and are happy when you keep them in large groups. However, you should avoid keeping them in pairs. The minimum number you can keep together is one male and two females. You can keep a larger number than this, but make sure the females outnumber the males.

Dalmatian Molly Tank Requirement

Like every other molly, Dalmatians tank requirement exceeds the act of purchase, and tank set up. It covers the water quality, usage of heater and filter, plants and decorations, and many more. Generally, mollies need a high PH (slightly alkaline), and hard water. Their tank requirement include 70-82°F, 7-8 PH, and 10-25 dH.

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Water Quality

The influence of the quality of the aquarium tank on the health of mollies is underrated. To maintain high and appropriate water quality, make sure you add filter, and heater to your tank. This will help you to fully recycle your aquarium. Also, ensure you change the water at due time. In the aquarium tank, it is often referred to as, “acclimation”.

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Acclimation is a process that involves changing the environment. However, in this case, although you will be changing the tank water, you should still place your fish in constant water conditions. Moreover, you can change the water totally, by replacing your aquarium tank with new water, or you change up to half of the water. A filter will make the replacement process easy. However, you should bear in mind that, the temporary home of your fish, during the change process should be the same water condition with the previous home. This is also applicable to the new water. A sudden change in water conditions will stress your fish.


Quite a number of people have argued if fish keepers need to add salt to their aquarium tank or not. However, salt is not an important component as it were, but the addition of salt can make your fish healthier. Generally, mollies can thrive in freshwater, brackish, or marine water.

Plants and Decorations

Adding plants to your aquarium tank will serve as a hiding place for smaller fish, and your mollies fry. Example of plant you can add to your tank includes Vallisnera, Java moss, Java fern, and Anubias. Also, you can add decorations like rocks. However, ensure these are not too clumsy. As it will hinder your fish from moving freely, especially the big mollies.

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Dalmatian Mollies Tank Mates

Mollies are very active fish, but they are a little nippy. So, we recommend you don’t keep them with long-finned fish. Moreover, mollies are livebearers, that is, they don’t lay eggs. So, they are suitable for other livebearers fish. Compatible tank mates for mollies include; Guppies, Cherry barbs,

How Often Should I Feed My Dalmatian Molly?

Generally, mollies are voracious eaters. And they keep eating, as long as you continue to feed them. However, you need to be careful, as not to overfeed your fish. Overfeeding will make them inactive, and it will prevent your fish from moving around freely. Also, overfeeding will create a lot of mess in the tank. Which results from leftover foods. Lastly, overfeeding your fish may cause indigestion.

As much as mollies can eat almost anything you offer them, they are good to go with twice per day feeding. If you get too busy to feed them, still make sure you feed them at least once daily. However, once per day feeding is more suitable for adult mollies. As Dalmatian molly babies require you to feed them twice per day, for optimum growth and development.

Dalmatian Mollies Diet

Like other mollies, Dalmatians are omnivores. As they have a great preference for plant matter. Moreover, they are so particular about algae that grow on plants in an aquarium tank. Also, make sure your molly’s food is diversified. Moreover, they have a wide variety of food options you can choose from. Such as pellets, freshly blanched vegetables like spinach, frozen foods like mosquito larvae. The good thing about their food preference is the ability to eat almost anything you give them. As they are not picky eaters.

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Can Dalmatian Mollies Be Aggressive?

Dalmatian mollies are very peaceful fish and are often exhibit no aggressive trait. It has been a success story for aquarists who have kept Dalmatian mollies. However, it is vague to say all Dalmatian fish are generally peaceful. Although a large percent of them can be extremely gentle. But, it is safe to say that, some dalmatian mollies can be somewhat aggressive towards another. You can see this in big mollies, that tend to bully other tank mates. Also, male mollies can be aggressive towards each other. Which is often a fight for dominance, or territorial space. More reason why you need to provide adequate space for them.

Do Dalmatian Mollies Eat Algae?

Yes, Dalmatian mollies eat algae. In fact, their one their best foods. However, it’s one of the strategies you can employ in keeping your tank clean. Many people often thought mollies feed on plants in the fish tank, but they rather feed on the algae that grow on the tank.

Do Dalmatian Mollies Turn Black?

There is a black variety of mollies, but they are referred to as “common black molly”. Sometimes, Dalmatian mollies exhibit a color combination of the white and black body. However, the white color is usually dominant. In most cases, Dalmatian mollies appear to be white, with traces of silver linings. Moreover, not in any case has it been reported that Dalmatian mollies turn completely black.

Dalmatian Molly Behavior

Having established that Dalmatian mollies are non-aggressive species, some aquarists have confirmed a hierarchic order among mollies. However, this has not been proven, but I believe there should be some natural arrangement or respect among them. For if there is no structure among them, you might just expect to see dropped-dead fish every day. However, they may not be in proper order as humans. Usually, they exhibit this trait when a person observes them well. So, get to know your fish better by observing their way of life.

Not so good behavior that is common to mollies is their lack of parental care. It will shock you to see a “mother molly” eating her babies after birth. Some aquarists complain about not having to raise their molly fry. However, this bad behavior is what you can’t stop for them, you can only manage it. Needless to say, mollies can release about 40-100 fry at once. So, if they don’t eat up some of them, I guess plenty of mollies should be “flying” around. However, if you know you are capable of raising these babies.

Here is how to go about it.

  • Separate the pregnant Dalmatian molly – You should place the pregnant molly in another tank when she is close to giving birth. However, make sure you are not removing her at an early stage. As she may be too stressed. Which will likely lead to miscarriage? Moreover, frequent changes in water conditions can lead to shock.
  • Using a breeding box – You will observe the pregnant molly is close to her birth when her belly is protruded, or you see a darker spot close to her fin. At this point, place her in a breeding box. When she is giving birth, her fry escape through the holes, into the “nanny tank”, while she remains trapped. Moreover, ensure you Maintain the same water condition while making these changes. Also, using a heater will make this easier. However, you can place the fry back into the community aquarium, as long as its big enough not to fit into the adult mollies mouth.
  • Keeping the fry – Mollies babies require no special condition apart from that which you provide for their adults. However, make sure you grind their food to a powdered form, to ease digestion and chewing.

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Dalmatian Molly Lifespan

Mollies are not demanding, and they are pretty easy to keep. Unfortunately, many Dalmatian mollies die a premature death, which results from an inappropriate tank setup like tiny aquariums and bowls.

In conclusion, Dalmatian mollies are wonderful species, that every aquarist love to have around. Moreover, their males especially have interesting sights of displaying their beautiful color combinations.