Blue Emperor Tetra

Regular price

Please contact store for availability as this item is not available all year round.

Emperor tetra 

Scientific name: Nematobrycon palmeri

Common name: Emperor tetra

Family: Characidae

Usual size in fish tanks: 4 - 5 cm (1.57 - 1.97 inch)


Recommended pH range for the species: 6.3 - 7.4

Recommended water hardness (dGH): 5 - 18°N (89.29 - 321.43ppm)

0°C 32°F30°C 86°F

Recommended temperature: 23 - 27 °C (73.4 - 80.6°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Top levels


South America; Emperor tetras are to be found in the waterways of Colombia. The Emperor tetra inhabit slow moving water ways and as such this should be replicated in the aquarium.


The expected life span for Nematobrycon palmeri is 6 years.

Short description

Heavily planted tanks are well suited to this fish. To display their colouration properly, use a dark substrate. Only keep these with peaceful tank mates as they can be a bit nervous at times. They are an ideal addition to a community set up of similar sized species of fish that also have a peaceful disposition. Larger species of fish will see these as a food source. They are best kept in groups of at least 8 specimens, this will also allow them to display their natural swimming patterns and behaviour. Like all of the tetra species the males will squabble to sort out a dominancy order but these are quite peaceful and no physical damage will occur between the rival males.

The males display a beautiful colouration that stands out in the group, providing them with ideal conditions will display them at their best. Like all species of fish they do require high water quality so make sure that the filtration system is rated for the aquarium and perform regular water changes on a weekly basis.

Food and feeding

Emperor tetras will accept any foods. Use a quality flake for the staple diet and include live or frozen foods for treats. Daphnia, blood worms and brine shrimp are ideal. Live foods given as treats will also help to bring out the best colouration in the fish.


The females are smaller than the males but have a rounder body shape. The males will have extended dorsal and caudal fins. The males should possess an extended ray in the middle of the caudal fin as well.


Add some spawning mops or fine leaved plants to the breeding tank, only keep one breeding pair in the tank at a time as the males will become aggressive to other males. Spawning will commence at daybreak and may last for several hours. Once the eggs have been laid, remove the parents and the eggs should hatch in 1-2 days. When the fry are free swimming they can be fed on Infusoria or newly hatched brine shrimp.

Dimmed lighting will help with the breeding process as this will settle the parent fish quicker, always use an air driven sponge filter as this will allow you to slow the water flow right down and aid the male when fertilising the eggs.

Conditioning the parent fish will also help in the breeding process and this should be undertaken before the males and females are joined in the breeding tank, prior to this the two sexes should be kept separated.