TankBud

Ruby moenkhausia

Moenkhausia rubra

Also known as Rubra tetra, Blue sapphire tetra

FreshwaterFish

Ruby moenkhausia (Moenkhausia rubra)

Care at a glance

Temperature
73–82°F
23–28°C
pH
5.5–7.0
Adult size
2.1 in
5.4 cm
Minimum tank
20 gal
75 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Medium
Breeding
No record
Rarity
Rare
Family
Characidae
Origin
Upper Juruena basin, Brazil

Overview

The ruby moenkhausia is a peaceful schooling tetra for a planted, soft-water community tank. It is best with a little experience.

Did you know

The ruby moenkhausia's red is natural breeding color, not a dye or a dyed-food trick. It deepens as fit males mature and display, and it grows richer the more settled the group is.

Caring for the ruby moenkhausia

Keep the ruby moenkhausia in a group of at least eight, and more if you can, in 20 gal (75 L) or larger. Give it planted margins with open swimming space in the center, and some gentle flow. A darker substrate with some driftwood and leaves shows off the fish and keeps it comfortable.

It needs soft, gently acidic water at 73 to 82°F (23 to 28°C) and a pH of 5.5 to 7.0. Feed a varied diet of small foods, such as quality flake and micro-pellets. Frozen bloodworm, daphnia and brine shrimp help bring out the red.

The ruby moenkhausia swims mostly in the middle of the tank and is peaceful. Keep it with other calm, similarly sized fish. In a group the fish feel secure, and the males color up as they display to one another.

The red is strongest in breeding males. The ruby moenkhausia has not been documented spawning in an aquarium.

Good to know

Moenkhausia rubra is a characin of the family Characidae, described only recently, in 2014, from headwater streams of the rio Juruena. Its name, rubra, is Latin for red and points to the reddish tones that spread through the body and fins.

In the wild

The ruby moenkhausia comes from the upper rio Juruena in the Tapajos basin of Brazil. It lives in clear, warm forest streams over sand and leaf litter.

Weekly picks

Tank mates

The ruby moenkhausia is a peaceful, schooling 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 ruby moenkhausia need?

A ruby moenkhausia needs at least 20 gal (75 L). It spends most of its time in the middle.

What temperature and pH does a ruby moenkhausia need?

A ruby moenkhausia is comfortable at 73–82°F (23–28°C) with a pH of 5.5–7.0.

What does a ruby moenkhausia eat?

A ruby moenkhausia eats a varied diet of small foods, such as quality flake and micro-pellets. Frozen bloodworm, daphnia and brine shrimp help bring out its red.

How big does a ruby moenkhausia get?

An adult ruby moenkhausia reaches about 2.1 in (5.4 cm).

Does a ruby moenkhausia need a group?

Yes. A ruby moenkhausia is a schooling species and should be kept in a group, not singly.

How can you tell a male ruby moenkhausia from a female?

Males color up as they display to one another, and the red is strongest in breeding males.

How does a ruby moenkhausia breed?

The ruby moenkhausia has not been documented spawning in an aquarium.

Related species