Marble Molly

Poecilia sphenops

Photo of aquarium fish Marble Molly
Natural range
  • Central America area
  • North America area
LivebearersConservation status: Least concern LC

Family:Poeciliidae

Other scientific names: Gambusia modesta, Gambusia plumbea, Lembesseia parvianalis, Mollienesia altissima, Mollienesia macrura, Mollienesia pallida

In English-speaking countries, the trade name “Marble Molly” or “Molly Marble” refers not to a specific breed of fish, but to a particular color variation. This pattern can be found in several selective forms, such as Poecilia velifera, Poecilia latipinna, Poecilia sphenops, as well as their hybrids.

Required aquarium volume
150 L
Size in aquarium
12 – 18 cm
Temperature
21 – 26 °C
Temperament
Peaceful (regular)
Parameters
Temperature21 – 26 °C
Water pHNeutral (7) – Slightly alkaline (8.5)
Water dHMedium hardness (10) – Very hard (30)
Water salinitymoderate (5–10 g/L)
Size in aquarium12 – 18 cm
Lifespan3 years
TemperamentPeaceful (regular)
Toward small fishnot a predator
Required aquarium volume150 L
Lightingany
Substrateany (no restrictions)
Water flowweak
FeedingMixed diet (meat + plant-based)
CareMixed (solitary / pair / group)

Frequently asked questions

The essentials: size, tank volume, water parameters and care

How big does Marble Molly get?

An adult reaches 12–18 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.

What size aquarium does Marble Molly need?

The minimum recommended volume is 150 L. A smaller tank speeds up nitrate build-up and raises stress levels.

What water parameters does Marble Molly need?

Temperature 21–26 °C, pH 7–8.5, hardness 10–30 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.

How long does Marble Molly live?

Around 3 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.

Is Marble Molly aggressive?

Temperament: peaceful (regular). Keep this in mind when choosing tank mates.

How many Marble Molly should be kept together?

Recommended setup: mixed (solitary / pair / group). Ignoring this is a common cause of stress and disease.

What does Marble Molly eat?

Diet type: mixed diet (meat + plant-based). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.

What is the scientific name of Marble Molly?

The scientific name of the species is Poecilia sphenops, family Poeciliidae. It also appears in the literature as: Gambusia modesta, Gambusia plumbea, Lembesseia parvianalis.

rev. 2a97a5b© Aquario 2024-2026Create by VR nine