Species profile
Blue Emperor Tetra
Inpaichthys kerri
Peaceful
Moderate care
70 L minimum aquarium
3.5–4 cm adult size
Midwater
Minimum group: 8
About this species
General notes for hobby use.
Small Brazilian tetra from tannin-stained tributaries. Prefers shaded soft acidic conditions and a decent social group.
Water parameters
Suggested general range for long-term care.
Temperature
24–27 °C
pH
5.5–7
GH
5–12 dGH
KH
Up to 8 dKH
Flow preference
Low–moderate
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 8
Tank zone
Midwater
Territory level
Low
Predation risk
Shrimp fry
Bioload factor
0.6
Peaceful group fish. Mature males display more strongly but serious aggression is limited; subdued décor and a larger shoal improve colour/confidence.
Compatibility flags
Quick cautions for common tank-planning issues.
Fin nipper
No
Plant safe
Yes
Shrimp safe
No / caution
Snail safe
Yes
Cave breeder
No
Digs substrate
No
Jump risk
Low
Natural history & care
Research-backed context for long-term aquarium care.
Lifespan
Not yet documented
Diet type
Omnivore
Minimum aquarium volume
70 L
Minimum footprint
60 × 30 cm
Accepted scientific name
Inpaichthys kerri
Alternative names
Blue Emperor Tetra, Royal Tetra, Inpaichthys kerri
Native range
Aripuanã River, upper Madeira River basin, Mato Grosso, Brazil.
Natural habitat
Sluggish clear but tannin-stained forest tributaries. Use driftwood/botanicals, dim-to-medium light and soft acidic water.
Diet & feeding
Small omnivore/invertivore; feed fine dry foods plus small frozen/live invertebrates.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males have a blue adipose fin and are slimmer/more colourful; females have a red-orange adipose fin and fuller body.
Breeding
Open-water/substrate egg-scatterer with no parental care; adults should be separated from eggs if breeding deliberately.