Species profile
Phoenix Tetra
Hemigrammus filamentosus
Peaceful
Moderate care
50 L minimum aquarium
3–4 cm adult size
Midwater
Minimum group: 8
About this species
General notes for hobby use.
Small soft-water Amazonian tetra described in 2011. The legacy common name 'Firefly Tetra' was incorrect for this species.
Water parameters
Suggested general range for long-term care.
Temperature
26–28 °C
pH
5–7
GH
Not yet documented
KH
Not yet documented
Flow preference
Low
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 soft-water shoaler. Best in a larger group with subdued light, botanical/wood cover and similarly small companions.
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
4–4 years
Diet type
Omnivore
Minimum aquarium volume
50 L
Minimum footprint
60 × 30 cm
Accepted scientific name
Hemigrammus filamentosus
Alternative names
Phoenix Tetra, Firefly Tetra (legacy master name; incorrect for this species)
Native range
Amazonian South America; aquarium stock is associated with rainforest soft-water habitats.
Natural habitat
Soft acidic rainforest water. Provide dim light, wood/botanicals, plants and gentle filtration.
Diet & feeding
Small omnivore/invertivore; offer fine dry foods and small frozen/live invertebrates.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Sexual differences are subtle; mature females are generally fuller-bodied, while males tend to be slimmer and may show more developed fin extensions.
Breeding
Egg-scattering characin with no parental care; deliberate breeding requires soft acidic water and protection of eggs from adults.