Common name
Emperor tetra
Scientific name
Nematobrycon palmeri
Category
Freshwater fish
Group
Tetras and characins
Environment
Freshwater
Origin
Atrato and San Juan river basins of western Colombia
Care level
Beginner
Adult size
Up to about 4.2 cm standard length
Expected lifespan
4–6 years
Minimum housing
At least 90 L with dense edge planting and multiple male display areas
Temperature
23–28 °C
pH
5.5–7.5
Hardness / minerals
Soft to moderately hard
Salinity
Freshwater
Lighting
Subdued to normal lighting with planted shade
Placement / swimming zone
Middle water

Identity and search names

This profile applies to Nematobrycon palmeri. Confirm trade identity and preserve breeder, supplier or locality records where relevant.

Environment and housing

Mature planted aquarium with shaded edges, open mid-water and wood or leaf litter

Feeding and nutrition

Feeding ecology: Omnivorous micropredator taking small insects, crustaceans and varied fine prepared foods

Feeding routine: Offer varied small meals once or twice daily without allowing dominant males to exclude others

Breeding and reproduction

Egg scatterer among fine plants; adults may eat eggs and fry

Parental care: No parental care

System demands

Filtration: Use mature biological filtration sized for the adult stock and feeding load, with guarded intakes and a flow pattern the species can use without continual effort.

Aeration: Maintain strong gas exchange and stable dissolved oxygen, especially overnight, during warm weather, medication, crowding or any interruption to filtration.

Maintenance: Test ammonia and nitrite after changes or abnormal behaviour; remove waste from the occupied zone and perform regular water changes matched to temperature and mineral chemistry.

Detailed husbandry

Identity scope
This profile applies to Nematobrycon palmeri. Confirm trade identity and preserve breeder, supplier or locality records where relevant.
Adult size and space
Up to about 4.2 cm standard length. At least 90 L with dense edge planting and multiple male display areas. Plan around adult dimensions, activity, group size, aggression and waste production rather than sale size.
Social structure
Keep at least 8–10 with more females than males where possible; provide separated display areas for males
Swimming zone
Primary zone: Mid water. Keep that zone usable for movement, feeding and refuge.
Feeding ecology
Omnivorous micropredator taking small insects, crustaceans and varied fine prepared foods
Feeding plan
Offer varied small meals once or twice daily without allowing dominant males to exclude others
Water stability
Maintain 23–28 °C; pH 5.5–7.5; hardness/minerals: Soft to moderately hard. Stable oxygenation and nitrogen-cycle control matter more than chasing one exact number.
Habitat structure
Mature planted aquarium with shaded edges, open mid-water and wood or leaf litter
Compatibility plan
Peaceful community species of similar size; avoid persistent fin-nippers and highly boisterous feeders
Breeding plan
Egg scatterer among fine plants; adults may eat eggs and fry. Parental care: No parental care.
Quarantine
Quarantine new fish in a separate cycled aquarium with dedicated equipment. Match temperature and mineral chemistry gradually, confirm feeding and normal respiration, and never add transport water to the established aquarium.
Welfare checks
Maintain the stated adult space and social structure, verify feeding and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Adult males defend display patches and can repeatedly chase subordinates. A token group in a bare small tank is poor husbandry.
Biosecurity and release
Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.
Main risk
Adult males defend display patches and can repeatedly chase subordinates. A token group in a bare small tank is poor husbandry.
Adult Projected Load
Moderate for a proper school because adult males establish display territories and repeated feeding adds continuous oxygen and nutrient demand.
Filtration
Use mature mechanical and biological filtration with protected intakes and enough turnover for the adult group while preserving species-appropriate current and refuge.
Aeration
Provide strong gas exchange and backup aeration; increase oxygen support before warm weather, heavy feeding, crowding, medication or filter interruption reduces the safety margin.
Maintenance
Remove uneaten food and bottom waste, clean prefilters before flow falls, test ammonia and nitrite after changes, and perform regular temperature- and chemistry-matched water changes.
Overridable Warnings
School structure, male display space, stable water, oxygen and equal feeding access cannot be overridden.

Welfare and risk

Main risk

Adult males defend display patches and can repeatedly chase subordinates. A token group in a bare small tank is poor husbandry.

Maintain the stated adult space and social structure, verify feeding and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Adult males defend display patches and can repeatedly chase subordinates. A token group in a bare small tank is poor husbandry.

Non-overridable warning

School structure, male display space, stable water, oxygen and equal feeding access cannot be overridden.

Sources

Source note

CURRENT