Black Molly

Poecilia sphenops

Black Molly (Poecilia sphenops) — Easy care, Semi-aggressive, under Livebearer & Killifish. Minimum tank in the app: 24 US gal min; aim for 70–82°F and pH 6.8–8.2. The Black Molly is an engaging option for both novice and experienced aquarists, offering lively behavior and a striking appearance.

Black Molly (Poecilia sphenops) in a planted freshwater aquarium
Care levelEasy
TemperamentSemi-aggressive
Min tank size24 US gal min
pH range6.8–8.2
Temperature70–82°F
Max size4.7 in (12.0 cm)
Captive lifespan2–4 years
SchoolingYes · 6+ recommended

Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.

Natural distribution

Americas / Africa (varies)

  • Africa
  • South America
  • Central America & Mexico

Regional colours match the stocking calculator’s origin map.

Black Molly Tank Setup

Aim for a spacious layout that accommodates swimming space in the top and mid-zones while incorporating ample cover through plants and decorations to foster a sense of security. Utilize a fine substrate to mimic their natural habitat, and maintain moderate lighting to encourage healthy growth of aquatic plants, which also serve as hiding spots.

What Do Black Mollys Eat?

Black Mollies are generally competitive feeders but can adapt to various feeding regimens, benefiting from a diverse diet to enhance their coloration and health. Monitor for any signs of overfeeding or competition, as this can lead to stress or health issues, especially if food is scarce or unevenly distributed.

Black Molly Tank Mates

Ideal companions include other peaceful or similarly-sized livebearers and community fish. Watch for potential issues with species that display aggressive territorial behavior, as this can provoke stress among Mollies. When housed together, ensure a sufficient group size to mitigate aggression within their own ranks, as they thrive in shoals of at least six.

Are Black Mollys Good for Beginners?

In App-aquatic we file this under easy care. That still means a cycled tank, realistic stocking, and parameters that do not swing every weekend. Aquarists often underestimate the need for group dynamics, leading to isolation stress when kept in too small numbers. neglecting water quality or pH levels can exacerbate health problems, as Black Mollies are sensitive to rapid changes in their environment, especially in less stable setups.

Guides that pair with this fish

Browse species guides · Water parameters cheat sheet

Building a community? Run the full list through the stocking calculator before you add anything else.

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