Max Size: 4.5cm

Emperor Tetra (Nematobrycon palmeri)

The Emperor Tetra has a genuinely majestic appearance, and an affable personality to match.

This species is peaceful, active and tranquil and rarely shows aggression, though the male will compete with other males. It can be kept with many different species but avoid putting it with more abundant species, or it may be seen as food. It will fare much better when in the company of its own kind though.

The original Emperor Tetras are royal blue and purple and vibrant yellow, which shifts back and forth and shimmers. They also display a stripe that blends out into purple or blue that lightens near the fins and tail, which are yellow.

The Emporer tetras come in 4 other varieties which include Rainbow, Blue, Black and Red.


Emperor Tetra
Emperor Tetras
Emperor Tetra
Black Emperor Tetra
Emperor Tetra
Male Emperor Tetra

Emperor Tetra Variants

Black Emperor Tetra
Quick Facts
Scientific NameNematobrycon palmeri
Year Described1911
Other NamesBlue Emperor Tetra, Red Emperor Tetra, Rainbow Emperor Tetra, Black Emperor Tetra
OriginsBrazil, Colombia
Aquarium LevelBottom - Middle
Best kept asGroups 5+
Lifespan3-6 years
Water Parameters
Water TypeFreshwater
PH5.0 - 7.5
TDS50 - 250
73 - 80℉
22.8 - 26.7℃


In the home aquarium, the Emperor Tetra will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Sexual Dimorphism

It is relatively easy to differentiate male and female Emporer tetras.

The main difference between the sexes is the fact that the females have green eyes and the males have blue eyes.

The female is noticeably smaller and has a fatter abdomen than the male. The male possesses an elongated ray in the middle of its caudal fin and an extended dorsal and anal fin whereas the female does not.

Other Tetras of interest

Adonis Tetra(Lepidarchus adonis)
African Moon Tetra(Bathyaethiops caudomaculatus)
African Red Eyed Tetra(Arnoldichthys spilopterus)
Arowana Tetra(Gnathocharax steindachneri)
Black Darter Tetra(Poecilocharax weitzmani)
Black Line Tetra(Hyphessobrycon scholzei)
View all Tetras
Date Added: 03/08/2020 - Updated: 04/10/2022 15:49:49