Species profile
Sailfin Tetra
Crenuchus spilurus
Peaceful
Moderate care
80 L minimum aquarium
5–6.5 cm adult size
Bottom–mid
Minimum group: 6
About this species
General notes for hobby use.
Despite the common name, behaviour is unlike a typical midwater schooling tetra. Give males defined shelters and visual separation.
Water parameters
Suggested general range for long-term care.
Temperature
22–28 °C
pH
4.5–7
GH
1–8 dGH
KH
Not yet documented
Flow preference
Low
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 6
Tank zone
Bottom–mid
Territory level
Moderate
Predation risk
Shrimp fry
Bioload factor
0.6
Calm characin whose males defend small spawning territories. Best in a quiet, structured aquarium rather than a busy open community.
Compatibility flags
Quick cautions for common tank-planning issues.
Fin nipper
No
Plant safe
Yes
Shrimp safe
No / caution
Snail safe
Yes
Cave breeder
Yes
Digs substrate
No
Jump risk
Low
Natural history & care
Research-backed context for long-term aquarium care.
Lifespan
4–6 years
Diet type
Carnivore
Minimum aquarium volume
80 L
Minimum footprint
75 × 35 cm
Accepted scientific name
Crenuchus spilurus
Alternative names
Sailfin Tetra, Sailfin Characin
Native range
Amazon and Orinoco basins and Guiana Shield drainages.
Natural habitat
Shaded forest creeks and leaf-littered margins with very soft acidic water, submerged wood and little current.
Diet & feeding
Micropredator taking insect larvae, crustaceans and worms; use small live/frozen foods with suitable fine prepared foods.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males are larger with greatly extended dorsal/anal fins; females are smaller and less ornate.
Breeding
Pair/cave-associated spawner. Eggs are attached beneath leaves, wood or sheltered surfaces and the male guards the clutch.