TankBud

Cauca molly

Poecilia caucana

FreshwaterBrackishFish

Cauca molly (Poecilia caucana)
Ewout Knoester · CC BY-SA 4.0

Care at a glance

Temperature
77–86°F
25–30°C
pH
7.0–8.5
Adult size
2.4 in
6 cm
Minimum tank
16 gal
60 L
Temperament
Peaceful
Social behavior
Social
Swim level
Middle
Difficulty
Easy
Breeding
Livebearer · Easy
Rarity
Very rare
Family
Poeciliidae
Origin
Panama, Venezuela, Colombia

Overview

The Cauca molly is a peaceful wild molly that likes to live in a group. It is easy to keep in a community of calm fish with hard, alkaline water.

Did you know

Unlike the familiar sailfin mollies, the Cauca molly stays small. Its plain silvery body carries rows of small dark spots, a look closer to a wild guppy than a fancy molly.

Caring for the Cauca molly

Keep a handful of Cauca mollies, with more females than males, in a tank of 16 gal (60 L) or larger. A planted tank with open swimming space and gentle flow suits them, and good light grows algae for them to graze. They spend most of their time in the middle of the tank.

Give them warm, hard, alkaline water at 77 to 86°F (25 to 30°C) and a pH of 7.0 to 8.5. They take well to a little added marine salt, though it is not essential. Like most mollies, they graze hard on algae and aufwuchs. Feed a flake or pellet with plenty of vegetable content, plus occasional small frozen foods.

Cauca mollies are peaceful and mix well with other calm species. Males are slim and carry a gonopodium, a modified anal fin bent into a mating organ that fertilizes females internally. The larger females carry the embryos and give birth to live, free-swimming fry. Broods come often in warm, hard water, and the species is easy to breed.

Good to know

The Cauca molly, Poecilia caucana, is a true livebearer in the family Poeciliidae. It turns up now and then in the hobby because it breeds so easily.

In the wild

Poecilia caucana ranges through Panama, Colombia and Venezuela, in warm lowland streams, ditches and coastal lagoons. It moves between fresh and slightly brackish water, so it is used to hard, mineral-rich conditions.

Weekly picks

Tank mates

The Cauca molly is a peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a Cauca molly need?

A Cauca molly needs at least 16 gal (60 L). It spends most of its time in the middle.

What temperature and pH does a Cauca molly need?

A Cauca molly is comfortable at 77–86°F (25–30°C) with a pH of 7.0–8.5.

What does a Cauca molly eat?

A Cauca molly grazes hard on algae and aufwuchs. Feed it a flake or pellet with plenty of vegetable content, plus occasional small frozen foods.

How big does a Cauca molly get?

An adult Cauca molly reaches about 2.4 in (6 cm).

How can you tell a male Cauca molly from a female?

Males are slim and carry a gonopodium, a modified anal fin bent into a mating organ. Females are the larger sex.

How does a Cauca molly breed?

Cauca mollies are livebearers, and the females give birth to live, free-swimming fry. Broods come often in warm, hard water, and the species is easy to breed.

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