Expanded fish care

Common Molly 

Kingdom:  Animalia

Phylum:  Chordata

Class: Actinopterygii

Order:  Cyprinodontiformes

Family:  Poeciliidae

Genus: Poecilia

Species: Poecilia sphenops

Care level- Easy to Expert

Temperament and Behavior- Normally peaceful, not typically aggressive, active swimmers may become progressively nippy under stress or kept with aggressive fish.  

Lifespan- Up to 5 years  

Size- Up to 4 inches

Diet- Omnivores

Being Omnivores means that Molly fish need a good mix of animal and plant proteins. Offering high-quality, high-protein foods is a must to maintain proper health. Flakes are the most used and the staple of the fish room: Extreme Krill Flakes or granules like Fluval’s Bug Bites. Mollies also enjoy frozen and live foods, for instance, blood worms or baby brine shrimp. Don't offer the live foods as often, more as a treat. Mollies, I have kept, even though they are omnivores, enjoy pecking on algae and plants quite often. They do get fed Spirulina flakes and Veggie Rounds in their diet often. Feed smaller amounts frequently instead of one large meal to avoid uneaten, rotten food messing up your aquariums cycle. 

Minimum Tank Size- 15 gallons

pH- 7.0-8.2

Water Hardness- Harder water recommended 

Temperature -68-82 degrees Fahrenheit

Tank-mates- Other peaceful fish species, nothing that is aggressive or nips on fins. Avoid cichlids. Try a Dwarf Gourami, Guppies, or Platy Fish, and don't forget smaller Plecostomus- Bristlenose Plecos. Mainly nothing on the aggressive side and has compatible water conditions. 

Recommended group size- 3:1 male to female ratio. 

Males v. Females- Molly fish are no different from the other popular livebearers in the hobby of telling males and females apart. Molly fish are sexually dimorphic, meaning you can see a difference between males and females, usually just by looking at them. There are gender-specific characteristics between the two sexes, and females are traditionally characteristically larger and have less color.

In contrast, males are usually characteristically smaller. Male Molly fish have a modified anal fin that looks stick-like called a gonopodium, whereas female Mollies will have a triangular anal fin. If you choose to keep males and females together, there is a high likelihood you will see fry at some point. Mollies come in many color combinations and fin shapes to choose from when deciding what to keep. Whether in a species-specific tank or a colorful combination display of Dalmatian, Balloon, Sailfin, or Black Mollies. One of the great perks of Mollies is that you can keep them in a species-specific tank or a peaceful community tank. Black Mollies are the truest velvety black found in the fish hobby. Remember, Mollies can breed within the same species; they can crossbreed within the same genus. Unfortunately, the molly/guppy fry does not usually last or grow very large before perishing. From what I understand, the fry is sterile.

Fry- Molly Fish are tiny versions of their parents. Molly females have a wide range of brood sizes, ranging from under ten to over a hundred. No matter the brood size, remember that livebearers are prolific at reproducing. Even if you are only getting a few fry at a time, you can quickly build a Molly Fish colony if the females drop fry every month like most other livebearing fish species. Mollies are ovoviviparous, which allows them to hold sperm from the males. Meaning if your Molly female has been in the same tank as a male at any point, she is likely to be pregnant. If removed and no longer exposed to a male, there is a possibility the female may produce fry with no mate present. After successfully being exposed to each and mating, female Molly Fish internally fertilized their eggs. These eggs hatch inside the mother when ready, giving birth by dropping live fry. 

Tank Set-Up-Mollies that I have kept in freshwater in my fish room have done great. However, what sets them apart from other livebearers species is their ability to thrive when kept on the brackish side. The Mollies do visually better, typically with a half teaspoon of salt per 10 gallons (marine salt is more concentrated and provides more minerals than aquarium salt). That works for me; you will need to observe and do what works best for your Molly Fish. Even making this statement, I have again kept Molly Fish in freshwater. They were healthy and happy, and in fact, keeping them in outside tubs was when I had the most fry. You must do your research and observe what does best for the Molly Fish you choose to keep.

How to Identify a Molly- Sometimes, when looking at different Mollies and Platy Fish, it can be difficult to distinguish between the two livebearing species. The best way to tell the difference is to look for physical disparities. Usually, Mollies are a little larger than Platy. However, the best identifying trait I look for in Molly Fish is an upturned or upwards-facing mouth.