Care
The Emperor Tetra is an ideal species for the mature community aquarium. These beautiful, peaceful, shoaling fish should be housed in a well decorated tank that contains plenty of plants (rooted and floating) and spindly driftwood. Male fish sometimes spar with one another as they vie for the attentions of the females, but no real harm should ensue; the displays are very eye-catching as the colours of the male fish intensify and the elongated fins are spread wide. It is best to try and outnumber males with females wherever possible, which is easiest to achieve in larger groups. This will also have the added benefit of making the fish feel more secure, and will result in a more effective, natural looking shoal. Tankmates could include other species of similar size and temperament e.g. other small peaceable tetras,
Corydoras catfish, pencilfish, dwarf cichlids such as
Apistogramma or
Mikrogeophagus spp., and some of the dwarf Loricariids. There is one other species in the same genus as the Emperor Tetra, that being the Rainbow Tetra (
N. lacortei). These fish are quite similar in appearance, but easy to tell apart as male Rainbow Tetras have bright red irises. A black colour variant of the Emperor Tetra is sometimes offered for sale in the aquatics trade as Black Emperor Tetra. This was once thought to be a third species in the
Nematobrycon genus (
N. amphiloxus) but is now considered a colour morph and synonym of
N. palmeri. Another similar-looking fish, although from a different genus altogether, is the Blue/Purple Emperor Tetra (
Inpaichthys kerri).
Inpaichthys do not grow quite as large and also possess an adipose fin, which is not present in
Nematobrycon.
Feeding
Flake, micropellets, small frozen foods such as daphnia, brineshrimp and mosquito larvae.
Breeding
This species is easy to breed in the home aquarium. Small numbers of fry may appear from time to time in heavily planted aquaria, but if you wish to raise a larger number of young, a separate breeding aquarium should be set up. The water should be soft and acidic, ideally with a pH between 6.0-7.0 and a general hardness of <12 degrees, and filtered via a small air driven sponge filter. The temperature should be set at the higher end of their preferred range, and lighting kept subdued. Spawning mops or clumps of Java moss should be placed on the bottom of the aquarium, and a well-conditioned male and female carefully acclimatised across. The fish should spawn the following morning, with just a few eggs scattered at a time, over the course of several hours. The adults are non-guarders and should be removed after spawning to prevent predation on the eggs. The eggs should hatch within 24-36 hours (depending on temperature of the water), with the fry becoming free-swimming some 4-5 days later. They should be offered infusoria as a first food, moving on to baby brineshrimp (
Artemia nauplii) and microworm as they grow.
