Dalmatian molly

Care at a glance

Overview

Mollies are social and do best in groups, with more females than males to spread out the attention. They are mostly peaceful and use the middle of the tank, needing around 90 liters because they get sizable. Keep them in the low to mid 20s C with hard, alkaline water near pH 7 to 8. They graze algae and need plant matter in the diet alongside flake and the odd frozen treat.

In the wild

Dalmatian mollies are a spotted form of the sailfin molly, which ranges through the southern United States and Mexico in fresh and brackish coastal waters. In the wild these fish handle hard, alkaline water and even some salt. At home they want hard, alkaline water and warmth, not soft acidic blackwater. A planted tank with open swimming room and some algae to graze suits them.

Good to know

This is a livebearer in the family Poeciliidae, the same group as guppies and platies. It reaches about 12 cm, with sailfin males growing a tall dorsal fin. Females give birth to live young rather than laying eggs, and they can drop a brood every few weeks once mature.

Did you know

They breed so easily that a mixed tank turns into a population boom on its own, and females can store sperm to keep producing broods for months after a single mating. Some keepers add a little aquarium salt, since the species tolerates and in some habitats prefers slightly brackish water.

Related species

• 

  Black molly

  Poecilia sphenops

  4.7 in (12 cm)24 gal (90 L)70–82°F (21–28°C)

• 

  Sailfin molly

  Poecilia latipinna

  4.7 in (12 cm)24 gal (90 L)70–79°F (21–26°C)

• 

  Liberty molly

  Poecilia salvatoris

  3.9 in (10 cm)24 gal (90 L)72–82°F (22–28°C)

• 

  Giant sailfin molly

  Poecilia velifera

  5.9 in (15 cm)30 gal (113 L)75–82°F (24–28°C)

• 

  Shortfin molly

  Poecilia mexicana

  4.3 in (11 cm)32 gal (120 L)72–82°F (22–28°C)

• 

  Gill's molly

  Poecilia gillii

  3.9 in (10 cm)26 gal (100 L)72–86°F (22–30°C)