Black Molly

Geographic Origin and Biotope: Commercial hybrid. The wild form (P. sphenops) comes from canals, coastal rivers and brackish water swamps of Central-South America (Mexico, Colombia). The Black Molly is the result of crossbreeding to fix melanism.

Taxonomy and Morphology: Black Molly (Poecilia sphenops). Lively poeciliid. Fusiform and hydrodynamic body, mouth adapted to scrape algae from surfaces. A very rustic strain (short-fin) compared to the sailfins.

Social Behavior: Incessant explorer and grazer. Wanders around the tank continuously "pecking" woods, glass and leaves. Males engage in relentless chases to mate, becoming bothersome if there are too few females.

Coloration and Sexual Dimorphism: Total Darkness. The color is an intense anthracite black over the entire body, fins included, almost velvety. If there are gold reflections, it is not a pure strain. Males (5 cm / 2 inches) with pointed gonopodium, females rounder and larger (7 cm / 2.7 inches).

Aquarium Setup: Spacious community tank (minimum 80 cm / 32 inches). Many robust plants (Vallisneria, Microsorum) and woods. They need free swimming. They appreciate a gentle water flow for oxygenation.

Diet and Feeding: Algae-grazing machine. Many buy them to eliminate filamentous or brush algae (BBA). In the tank they must follow a 70% vegetable diet (spirulina flakes, boiled zucchini, peeled peas) to avoid occlusions.

Water Quality: Lifesaving Salt. Mollies are not pure freshwater fish. They demand VERY HARD (GH 15-30) and alkaline (pH 8) water. Adding 1-2 teaspoons of marine salt per 10 liters (2.5 Gallons) will make them immortal; in soft freshwater, they will get "Shimmy" disease in a few days.

Compatibility and Tankmates: Excellent community dweller, provided everyone loves hard water. Perfect with Guppies, Platies, Swordtails. Not recommended pairing with Amazonian Characins (Neons) which need soft and acidic waters.

Aquarium Reproduction: Ovoviviparous. No nests or eggs. The female expels 20-60 large and black fry once a month, perfectly autonomous. Without hiding places, adults and tankmates will feast on them.

Risks and Diseases: The Shimmy Disease. Symptom of osmotic stress from water that is too soft (little calcium and salts). The Molly seems to swim in place rocking its head (like a snake), clamps its fins and eventually dies. It is cured instantly by adding mineral or marine salt.