Species profile
McCullochs Rainbowfish
Melanotaenia maccullochi
Peaceful
Moderate care
120 L minimum aquarium
6–8 cm adult size
Top mid
Minimum group: 8
About this species
General notes for hobby use.
Population forms vary in colour and pattern. Keep locality information with breeding stock where known.
Water parameters
Suggested general range for long-term care.
Temperature
20–26 °C
pH
5.5–7.5
GH
2–15 dGH
KH
Not yet documented
Flow preference
Moderate
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 8
Tank zone
Top mid
Territory level
None
Predation risk
Tiny fry
Bioload factor
1
Small active rainbowfish. Keep a good mixed-sex group with open swimming space and dense planting at the sides and rear.
Compatibility flags
Quick cautions for common tank-planning issues.
Fin nipper
No
Plant safe
Yes
Shrimp safe
Yes
Snail safe
Yes
Cave breeder
No
Digs substrate
No
Jump risk
Yes
Natural history & care
Research-backed context for long-term aquarium care.
Lifespan
5–8 years
Diet type
Omnivore
Minimum aquarium volume
120 L
Minimum footprint
90 × 35 cm
Accepted scientific name
Melanotaenia maccullochi
Alternative names
McCulloch's Rainbowfish, Dwarf Rainbowfish
Native range
Northern Australia and southern New Guinea, with geographically distinct populations.
Natural habitat
Swamps, creeks and small streams, often densely vegetated and seasonally variable.
Diet & feeding
Small invertebrates, algae and plant material; feed quality dry foods with regular frozen/live foods.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males are generally more colourful and deeper-bodied; females are plainer and fuller when gravid.
Breeding
Plant-spawning egg scatterer. Eggs are deposited among fine plants or spawning mops over many days and receive no parental care.