[8] The three different species of fish known as rummy-nose tetras have the following distributions: All three species of rummy-nose tetra inhabit river stretches whose water chemistry is mineral-deficient (soft), acidic, and frequently tainted with humic acid decay products from leaf litter upon the river substrates (known as 'blackwaters' because of their appearance).

Rummy-nose tetra while being able to perceive their environment better individually rather than in a group still has the ability to sense what the distance is between them and the nears member of the school, thus decreasing the risk of predation.

The rummy-nose tetra cannot be kept with other popular ornamental fishes, such as African cichlids, as they require very different water parameters.

Persistent paleness of the head is to be taken as a sign that water chemistry parameters in the maintenance aquarium are in need of adjustment, and that pollutant levels are becoming dangerous for the inhabitants.

Rummy-nose tetras present serious challenges even to experienced aquarists from the standpoint of breeding, primarily due to two factors: the likelihood of sterility ensuing if the prospective parents are maintained in water with too high a level of dissolved calcium ions, and the slow growth rate of the fry.

The breeding aquarium for the rummy-nose tetra, in addition, needs to be sterilised prior to use, as the fish produces eggs that are notoriously sensitive to bacterial and fungal infection.

Use of an antifungal agent is strongly advised once spawning is completed in order to prevent various fungi from attacking the eggs.

Furthermore, it is highly advisable to filter the water of the breeding aquarium over peat, or alternatively use one of the commercially available 'Blackwater Tonic' additives to provide the necessary chemical environment conducive to reproduction.

The parents should be introduced to the breeding aquarium up to 7 days before spawning, fed heavily with live foods, and kept under subdued lighting.

In addition, the parents tend to prefer to spawn under quiet conditions, and thus the aquarium should be sited away from areas of busy human traffic.

The species is not noted as a particularly egregious egg eater (unlike, for example, the lemon tetra) but it is still advisable to remove the parents once spawning is completed.

At this stage, antifungal agents to protect the eggs should be added, and indeed are vital in the case of this difficult, sensitive species.

It can take as long as 6 months to raise fry to juvenile sizes where they are capable of eating live daphnia on a regular basis.

Taking all of these factors into account, the fish is a major breeding challenge for the aquarist, and success may depend at least partly upon luck.