Emperor Tetra

Nematobrycon palmeri

Also known as: Emperor

Water Parameters

• Temperature: 23–27°C
• pH: 5.5–7.5
• Hardness (GH): 36–179 ppm (2–10 dGH)

Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.

Care Summary

One of the more characterful small tetras, the emperor wears a steely purple-to-blue body crossed by a bold dark stripe, the males distinguished by gem-blue eyes and a central tail extension that gives a three-pronged trident shape. Rather than schooling tightly it drifts in a loose group in which males pose and fence for status, which gives a planted tank a quiet, regal sort of life. It is hardy, peaceful toward other species, and undemanding once given soft to moderately-hard water and the company of its own kind. Long-lived for a small tetra and reliably tank-bred, it is an easy, slightly more interesting alternative to the usual schooling fish.

Tankmates

Peaceful toward other fish, but the males are gently territorial with one another, displaying and sparring without real harm, so keep a group of at least six with several males to spread that behaviour around. It is a loose-grouping rather than a tight-schooling tetra, drifting through the mid-water in a relaxed shoal. Compatible with most peaceful community fish, corydoras, dwarf cichlids like the german blue ram, and adult shrimp. Avoid fin-nippers and large or boisterous tankmates. A planted, dimly-lit tank deepens the colour.

Compatible with

• Neon Tetra
• Harlequin Rasbora
• Bronze Corydoras
• Ember Tetra
• Otocinclus
• Cherry Shrimp
• Honey Gourami
• German Blue Ram

Avoid keeping with

• Betta
• Angelfish
• Large Cichlids
• Fin Nippers
• Tiger Barb

Common Problems

• male sparring in tanks without enough space or females
• faded colour in bright, bare tanks
• ich
• stress from boisterous tankmates

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20