Species profile
Harlequin Rasbora Variant
Trigonostigma heteromorpha
Peaceful
Easy care
60 L minimum aquarium
3.5–5 cm adult size
Midwater
Minimum group: 8
About this species
General notes for hobby use.
Domestic Harlequin Rasbora form. The old catch-all “Trigonostigma hybrid” label is too broad and risks mixing distinct rasbora species.
Water parameters
Suggested general range for long-term care.
Temperature
22–26 °C
pH
5–7
GH
Up to 12 dGH
KH
Not yet documented
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
None
Predation risk
Shrimp fry
Bioload factor
0.45
Peaceful shoaling rasbora. Group size and shaded cover matter more than defending territory; keep away from large predatory tankmates.
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
Yes
Natural history & care
Research-backed context for long-term aquarium care.
Lifespan
Not yet documented
Diet type
Omnivore
Minimum aquarium volume
60 L
Minimum footprint
60 × 30 cm
Accepted scientific name
Trigonostigma heteromorpha
Alternative names
Harlequin Rasbora Variant, Harlequin Rasbora, Trigonostigma heteromorpha domestic form
Native range
Captive domestic form of T. heteromorpha; parent species native to southern Thailand, Peninsular Malaysia, Singapore and Sumatra.
Natural habitat
Parent species favours shaded forest streams/swamps. Use gentle flow, plant/wood cover, subdued zones and preferably soft slightly acidic water.
Diet & feeding
Small omnivore/insectivore; feed fine dry foods plus small frozen/live invertebrates.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Mature females are generally deeper-bodied; males are slimmer and the dark wedge is often sharper/more angular.
Breeding
Deposits adhesive eggs on the underside of broad leaves; no parental care and adults may eat eggs/fry.