The black molly (Poecilia sphenops) is a hybrid variation of the sailfin molly. It is a small fish, with males reaching about three inches in length and females slightly smaller.
Difficulty: The black molly is fairly easy to keep in a community tank that doesn’t include more aggressive fish. An ideal environment would include several females to a single male, as a lone female will often get harassed by a single male. Two males in the same tank will fight. Because the molly eats primarily plant material and algae, plants are highly recommended. The black molly, like most all mollies, can live in fresh, brackish, and saltwater aquariums. Salt is recommended for black mollies living in freshwater aquariums. The general rule is one teaspoon for each gallon of water.
Hardiness: Their ideal pH requirements range from 7.5 – 8.2 with a water temperature ranging from 70-82 degrees Fahrenheit. A mid-to-top-level fish, the black molly is an algae eater that will eat the green algae in your tank. Conversely, the black molly can be fed most dried foods that float at the top. It also accepts vegetable-based frozen foods, as well as blanched vegetables such as lettuce and cucumber. It feeds at the surface. This fish thrives in a well planted tank.
Range: The black molly comes primarily from fish farms and often breed in the aquarist’s tank. The fish should be well fed prior to breeding. A livebearer, the black molly will eat its fry, so it is important that floating plants are in the tank so the fry can hide in the event you are not present at birth. As soon as you see fry swimming about, place them in a breeder net or move them into their own aquarium.
Aquarium conditions: A 20 gallon aquarium is a good minimum size for this fish. The larger the tank, the more stable the water. Filtration that does not disturb the surface is ideal as the black molly enjoys skimming the surface with its mouth, looking for food to eat. A heater is also required to keep the water at an ideal temperature. Tankmates should be of the non aggressive type, and bear in mind that the fish can be a prolific breeder so don’t be surprised if you wake up one day and see little black dots swimming about.