Dalmatian Molly (Poecilia sphenops) in a freshwater aquarium
Easy careSemi-aggressiveSchool of 6+Americas / Africa

Dalmatian Molly

Poecilia sphenops

The Dalmatian Molly (Poecilia sphenops) is a semi-aggressive fish that's easy to keep. Give it a tank of at least 90 litres (24 US gallons), water held at 70-79°F, and a pH of 6.8-8.2. Always keep a group of at least 6 - they feel safest in numbers.

Care levelEasy
TemperamentSemi-aggressive
Min tank size24 US gal
pH range6.8-8.2
Temperature70-79°F
Max size4.7 in (12.0 cm)
Captive lifespan2-4 years
SchoolingYes · 6+ recommended
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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.

Dalmatian Molly Tank Setup

A tank of at least 90 litres (24 US gallons) at 70-79°F and pH 6.8-8.2 suits them well. Livebearers breed quickly, so plan for the fry and keep an eye on your male-to-female ratio. Always keep a group of at least 6 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour. They reach about 12 cm as adults, so don't be misled by the small juveniles sold in stores.

What Do Dalmatian Mollies Eat?

They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.

Dalmatian Molly Tank Mates

Keep in groups of at least 6. The Dalmatian Molly is semi-aggressive, which is the first thing to weigh up when you choose tank mates. It's a shoaling fish, so settle a group of 6 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.

Are Dalmatian Mollies Good for Beginners?

Often recommended to beginners, but only after the tank is cycled and you can keep a proper school - not three fish in a new setup.

Dalmatian Molly - frequently asked questions

What size tank do Dalmatian Mollies need?

Dalmatian Mollies need a tank of at least 90 litres (24 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.

How many Dalmatian Mollies should I keep together?

Keep a group of at least 6. Dalmatian Mollies are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.

What water parameters do Dalmatian Mollies need?

Keep them at 70-79°F with a pH of 6.8-8.2, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.

What do Dalmatian Mollies eat?

Dalmatian Mollies are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.

Are Dalmatian Mollies good for beginners?

Yes - Dalmatian Mollies are a good beginner choice once the tank is fully cycled and you can keep a proper group. They are hardy but still need stable water and a school to feel secure.

Common mistakes with Dalmatian Mollies

  • Buying fewer than 6 - Dalmatian Mollys need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.

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

Fish to avoid mixing with Dalmatian Mollies

These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.

  • OscarPredator - Oscar will eat or injure smaller tank mates
  • Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
  • Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates