Encyclopaedia
Black Molly
Poecilia sphenops var. Black
The Black Molly is the embodiment of perfect melanism in aquariums. However, the myth of its hardiness is false. These fish evolved in estuaries, where the sea meets rivers. They demand extremely hard, alkaline, and very warm water (26°C), often with added marine salt (brackish). Putting them in a normal soft-water aquarium equals dissolving their immune system. They will start to rock in place ("Shimmying"), and then cover themselves in lethal white spots (Ich) within hours due to osmosis destroying their protective mucus.
Share
Check out Black Molly on Atlarium
22 - 28 °C
7.5 - 8.5
Freshwater / Brackish
Surface and middle
7 cm
>= 80 L
>= 4
15 - 30 dGH
7 - 15 dKH
295 - 600 ppm
461 - 938 uS/cm
Species description
Care, breeding and tankmates
Geographic Origin and Distribution
Origin
Fish profile
- Temperament
- Active
- Diet
- Omnivore
- Sex ratio
- Specific M:F ratio
- Feeding frequency
- Twice daily
- Bioload
- They produce a moderate to high bioload, especially when compared to smaller livebearers. This is due to their relatively robust size and hearty appetite. Efficient filtration and regular water changes are crucial to process their waste effectively. Inadequate tank maintenance can lead to a quick buildup of harmful nitrates. Monitoring their population size is also important, as their breeding can compound the bioload significantly.
- Flow
- Stagnant
- Reproduction
- Oviparous
- Compatibility & tankmates
- Harem only
- Tank level
- Top/Middle
Window to the official scientific data of the species
Scientific Parameters & Models
- Trophic level
- 3 ± 0.34 se
- Resilience
- High (less than 15 months)
- Phylogenetic uniqueness (PD50)
- 0.5
- Bayesian Length-Weight
- a = 0.01514, b = 3.12
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Recommendations grouped by close relatives, companion choices, and similar care.
Variants and close relatives
Same atlas type, nearby scientific identity, genus, or family.
Recommended companions
Compatible cards from coherent ecosystems with matching parameters.
Similar care
Cards with similar requirements, difficulty, habitat, and husbandry profile.















































