Max Size: 6cm

Copei Tetra (Moenkhausia copei)

Copei Tetras are a peaceful and very sociable community fish. These Tetras are schooling fish and will thrive if kept in a larger group of at least ten individuals, and they will express a more natural behaviour as well as better colours. However, males will form a hierarchy, and watching a mixed-gender group with a slightly female-biased ratio is fascinating as the males are continually seeking to attract the attention of the females.

Copei Tetras prefer a densely planted aquarium containing a sandy substrate and a few dried leaves on the bottom. They also require plenty of swimming space and some subdued lighting.

Copei Tetras can live in a community aquarium with many different species without difficulty. The ideal tankmates would be other South American characins and bottom-dwellers. However, it would be best if you did not house these Tetras with much larger or more aggressive species otherwise, they will get stressed and outcompeted for food.

Copei Tetras have a silvery elongated body with a yellowish gold sheen on the lower half. These fish also have prominent red colouring on their caudal and adipose fin. In some individuals, the dorsal fin can show some colour, but usually, they are transparent along with their pectoral, pelvic and anal fins.

Quick Facts
Scientific NameMoenkhausia copei
Other NamesTetra Copei, Red Tail Tetra
OriginsPeru, Venezuela
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 10+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH6.0 - 7.5
GH10 - 20
TDS18 - 268
72 - 79℉
22.2 - 26.1℃


Copei Tetra
Copei Tetra

Natural Habitat

Copei Tetras are endemic to the Rio Orinoco and Amazon River Basin in South America. Due to their significant habitat, you will find several colour variations of this species. For example, fish from Venezuela display bright red colouring, whereas those from Peru are not as bright, displaying more of a light orange colouration.

These Tetras inhabit moderately fast-flowing, shallow parts of clear rivers with sandy bottoms. These fish typically occur in sheltered areas amongst decaying, submerged trees and aquatic vegetation.



In the wild, Copei Tetras feed on insects, micro-crustaceans and plants. In captivity, these Tetras are easily fed and will readily accept most types of aquarium foods.

Copei Tetras will take high-quality dried foods such as flakes, granules, and pellets; however, it would be beneficial to provide them with plenty of live and frozen foods for your fish's best colour and condition. These can include blackworm, bloodworm, daphnia and brine shrimp.

Sexual Dimorphism

It is relatively straightforward to differentiate between the male and female Copei Tetras. The males are usually slimmer and more colourful than the females and, in breeding conditions, display a solid humeral spot. In contrast, females are slightly larger and have rounder bodies than males.


It is challenging to reproduce Copei Tetras in captivity successfully. However, like most Moenkhausia species, if they are in good condition, they can spawn in a community aquarium, and small numbers of fry may start to appear without any human intervention. However, like all Tetras, they are egg scattering free spawners that present no parental care.

If you would like to produce a higher yield of fry, it would be better if you prepared a separate breeding tank. The breeding tank will need dim lighting and established water, and plenty of plants. Spawning mops will work just as well. However, it would be better if you also conditioned the breeding pairs with plenty of live, frozen or freeze-dried foods such as bloodworm or mosquito larvae; this will help to encourage reproduction.

When females are ready to spawn, you will notice them swimming more actively around the tank and the males bumping into them. The females will then swim amongst the plants, scattering their eggs as the males swim behind them, fertilising the eggs.

Typically when the females lay their eggs, they will attach them to plants. However, some eggs may drop to the bottom of the tank. Females can lay several hundred eggs during a single spawning.

Once the females have stopped scattering their eggs and the males have fertilised them, it is advisable to remove the adults from the breeding tank because they will have nothing more to do with the eggs, and they may consume them if given a chance.

It would be better to keep the lights off and the tank dark as Tetra eggs and fry are especially susceptible to the light.

Generally, the eggs will hatch in 24 to 48 hours depending on the condition of the water and the temperature; then, three to four days after that, the fry will become free-swimming. After the first week or so, you may gradually start to increase the lighting.

The newly hatched fry will first feed on their yolk sac but, once they have consumed their yolk sack and become free-swimming, you can provide them with infusoria or rotifers moving on to baby brine shrimp and crushed flakes as they grow.

Other Tetras of interest

African Moon Tetra(Bathyaethiops caudomaculatus)
African Red Eyed Tetra(Arnoldichthys spilopterus)
Black Darter Tetra(Poecilocharax weitzmani)
Black Line Tetra(Hyphessobrycon scholzei)
Black Neon Tetra(Hyphessobrycon herbertaxelrodi)
Black Phantom Tetra(Hyphessobrycon megalopterus)
View all Tetras
Date Added: 29/09/2021 13:50:33 - Updated: 22/11/2021 17:05:06