
Source: Wikimedia Commons
Nematobrycon palmeri
A small characin, greyish purple with a black lateral stripe and long dorsal, anal and caudal fins. The central ray of the caudal fin is extended too, giving a three-pronged tail. The male's iris is blue, the female's green.
Nematobrycon palmeri is a small characin from the Atrato and San Juan basins of southwestern Colombia. FishBase gives 4.2cm SL, pH 5.0-8.0, 5-19 dH and 23-27C, and recommends groups of five or more in a tank of 80cm or longer, while Seriously Fish gives 23-27C, pH 5.0-7.5, 1-12 dGH and a base of at least 90 by 30cm. The body is greyish purple with a black lateral stripe, and the dorsal, anal and caudal fins all extend. Unusually for a characin the central ray of the caudal fin is extended too, so the tail reads as three-pronged. Males are larger and more strongly coloured with longer fins and a blue iris; the female's iris is green. Hardy, inexpensive and even-tempered, it is treated as a beginner's fish, though rival males hold territories and need room and cover. Most fish on sale are farmed, and wild ones are less common than they once were.
Source: Wikipedia (CC BY-SA 4.0)
The Emperor Tetra lives 3-5 years.
The Emperor Tetra grows to About 4.2cm.
The ideal temperature for the Emperor Tetra is 23〜27℃.
Origin
South America (southwestern Colombia, the Atrato and San Juan river basins)
Lifespan
3-5 years
Sources: Seriously Fish / FishBase
Edited & verified by: BreederDirect editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Sources: CITES Appendices (species not listed) / IUCN Red List
Regulations may change. Always verify the latest information with the relevant authorities.
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Size
About 4.2cm
Temperature
23〜27℃
Dried foods, frozen bloodworm, Daphnia, brine shrimp
Seriously Fish suggests a base of at least 90 by 30cm, about 81 litres at 30cm depth, and FishBase likewise recommends 80cm or more. Rival males hold territories, so several sight breaks of plants and wood keep the disputes mild.
Seriously Fish gives 23-27C, pH 5.0-7.5 and 1-12 dGH; FishBase gives a slightly wider pH 5.0-8.0 with 5-19 dH and 23-27C. Most fish are farmed and tolerate a broad range.
Lively and peaceful, it suits a general community and mixes with other tetras, Corydoras, small loricariids, gouramis and dwarf cichlids. Do not keep it with fish large enough to see it as food. Keep six or more, preferably ten or more. Rival males dispute territories, but no serious damage is done in a tank with enough room.
It takes dried food but should not live on it alone. Daily meals of small live and frozen fare such as bloodworm, Daphnia and brine shrimp bring up the colour and encourage breeding condition. FishBase records worms and crustaceans in the wild.
Breeding is not difficult. Use a dimly lit separate tank of about 40 by 20 by 20cm with fine-leaved plants or a spawning mop, and remove the adults as soon as eggs appear. The eggs hatch in twenty-four to thirty-six hours and the fry swim four to five days later. Spawn in pairs for numbers, or in a group in a tank large enough for the males' territories.
FishBase lists it as IUCN Data Deficient, not on the CITES appendices and harmless to people. It is sometimes confused with the congeneric N. lacortei, but the male's iris is blue here and red in that species. Kept in small numbers it shows neither its proper colour nor its proper behaviour.
Beginner. This is a beginner-friendly species. No special equipment or experience is required, and it can be kept successfully with basic care setup.
The ideal temperature for Emperor Tetra is 23〜27℃. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Emperor Tetra is 3-5 years. With proper care and nutrition, they can live a long and healthy life.
Emperor Tetra typically reaches About 4.2cm as an adult. Size may vary depending on care conditions and individual genetics.
Emperor Tetra feeds on: Dried foods, frozen bloodworm, Daphnia, brine shrimp. Aim for a balanced diet with appropriate feeding frequency.
The price of Emperor Tetra varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
Last updated: September 17, 2026