TankBud

Merry widow livebearer

Phallichthys amates

FreshwaterFish

Merry widow livebearer (Phallichthys amates)
Arturo Angulo, Beatriz Naranjo-Elizondo, Emmanuel Rojas, and Juan Manuel Ley-López · CC BY 4.0

Care at a glance

Temperature
72–86°F
22–30°C
pH
7.0–8.0
Adult size
2.5 in
6.4 cm
Minimum tank
16 gal
60 L
Temperament
Peaceful
Social behavior
Social
Swim level
Middle
Diet
Omnivore
Difficulty
Easy
Breeding
Livebearer · Easy
Rarity
Very rare
Family
Poeciliidae
Origin
Guatemala, Panama

Overview

The merry widow livebearer is a gentle, easygoing fish for a peaceful community tank. It is undemanding and a sound choice for someone new to wild livebearers.

Did you know

The merry widow livebearer's genus name, Phallichthys, means penis fish. It is a blunt reference to the male's very long gonopodium, which can reach a large fraction of his own body length.

Caring for the merry widow livebearer

Keep merry widow livebearers in a small group in a tank of 16 gal (60 L) or larger. Give them a well-planted tank with open swimming areas, gentle flow and steady filtration.

They prefer hard, mineral-rich water, neutral to alkaline, at 72 to 86°F (22 to 30°C) and a pH of 7.0 to 8.0. They are not fussy, but clean, stable water keeps them healthy and breeding freely.

Merry widow livebearers graze soft algae and take almost any small food. Feed a good flake with some vegetable content, plus occasional frozen daphnia or bloodworm. They are peaceful and share the middle of the tank with other calm species.

Keep more females than males, as males court often. Males stay smaller than females, and a male carries an unusually long gonopodium, which he uses to fertilize the female internally. Females give birth to live young and breed readily, which makes this an easy livebearer for a home tank.

Good to know

The merry widow livebearer, Phallichthys amates, belongs to the livebearer family Poeciliidae. The male's gonopodium is a modified anal fin.

In the wild

The merry widow livebearer ranges from Guatemala down to Panama. It lives in warm, slow to moderate streams, ponds and ditches, often among thick plants.

Weekly picks

Tank mates

The merry widow livebearer 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 merry widow livebearer need?

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

What temperature and pH does a merry widow livebearer need?

A merry widow livebearer is comfortable at 72–86°F (22–30°C) with a pH of 7.0–8.0.

What does a merry widow livebearer eat?

A merry widow livebearer grazes soft algae and takes almost any small food. Feed it a good flake with some vegetable content, plus occasional frozen daphnia or bloodworm.

How big does a merry widow livebearer get?

An adult merry widow livebearer reaches about 2.5 in (6.4 cm).

How can you tell a male merry widow livebearer from a female?

Males stay smaller than females, and a male carries an unusually long gonopodium.

How does a merry widow livebearer breed?

A merry widow livebearer gives birth to live young after the male fertilizes the female internally. Females breed readily, so it is an easy livebearer for a home tank.

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