Common name
Crimson-spotted rainbowfish
Scientific name
Melanotaenia duboulayi
Category
Freshwater fish
Group
Rainbowfish and blue-eyes
Environment
Freshwater
Origin
Eastern coastal drainages from northern New South Wales to southern Queensland, Australia
Care level
Beginner
Adult size
Usually under 10 cm, with a documented maximum around 12 cm standard length
Expected lifespan
5–8 years
Minimum housing
At least 240 L with a long oxygenated swimming footprint for a group of eight or more
Temperature
18–28 °C
pH
5.8–8.2
Hardness / minerals
Soft to hard; stable mineral content is more important than a narrow target
Salinity
Freshwater
Lighting
Normal aquarium lighting
Placement / swimming zone
Species dependent

Identity and search names

Single-species profile for Melanotaenia duboulayi; locality strains should retain provenance and must not be mixed with other rainbowfish.

Environment and housing

Open swimming area, good oxygenation, plants around the edges and a secure lid

Feeding and nutrition

Feeding ecology: Omnivore; varied quality dry food with plant and invertebrate foods

Feeding routine: Small appropriate meals based on age and body condition

Breeding and reproduction

Adhesive egg scatterer in plants or spawning mops

Parental care: No parental care; adults may eat eggs or fry

System demands

Filtration: Use mature biological filtration sized for the adult stock and feeding load, with guarded intakes and a flow pattern the species can use without continual effort.

Aeration: Maintain strong gas exchange and stable dissolved oxygen, especially overnight, during warm weather, medication, crowding or any interruption to filtration.

Maintenance: Test ammonia and nitrite after changes or abnormal behaviour; remove waste from the occupied zone and perform regular water changes matched to temperature and mineral chemistry.

Detailed husbandry

Identity scope
Single-species profile for Melanotaenia duboulayi; locality strains should retain provenance and must not be mixed with other rainbowfish.
Adult size and space
Usually under 10 cm, with a documented maximum around 12 cm standard length. At least 240 L with a long oxygenated swimming footprint for a group of eight or more. Plan around adult dimensions, activity, group size and waste production rather than sale size.
Social structure
Keep 8+ with both sexes represented
Swimming zone
Primary zone: Mid and upper water. Keep this zone open for movement, feeding and refuge.
Feeding ecology
Omnivore; varied quality dry food with plant and invertebrate foods
Feeding plan
Small appropriate meals based on age and body condition
Water stability
Maintain 18–28 °C; pH 5.8–8.2; hardness/minerals: Soft to hard; stable mineral content is more important than a narrow target. Stable oxygenation and nitrogen-cycle control matter more than chasing one exact number.
Habitat structure
Open swimming area, good oxygenation, plants around the edges and a secure lid
Compatibility plan
Active peaceful community fish that tolerate the same broad conditions
Breeding plan
Adhesive egg scatterer in plants or spawning mops. Parental care: No parental care; adults may eat eggs or fry.
Quarantine
Quarantine new fish in a separate cycled aquarium with dedicated equipment. Match temperature and mineral chemistry gradually, confirm feeding and normal respiration, and never add transport water to the established aquarium.
Welfare checks
Use the adult housing and social plan in this profile, monitor body condition and behaviour, and correct measured water or compatibility problems early. An active native schooling fish that needs length and good oxygen—not a small “local” tank.
Biosecurity and release
Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.
Main risk
Maintain locality records and never mix or release stock. This Australian native has regionally distinct populations and must not be collected, moved or released without lawful authority.
Adult Projected Load
Moderate for the planned adult stock. Calculate filtration, oxygen and swimming space from the full adult size (Usually under 10 cm, with a documented maximum around 12 cm standard length) and social group (Keep 8+ with both sexes represented), not the juvenile sale size.
Filtration
Use mature mechanical and biological filtration with protected intakes and enough turnover for the adult group while preserving species-appropriate current and refuge.
Aeration
Provide strong gas exchange and backup aeration; increase oxygen support before warm weather, heavy feeding, crowding, medication or filter interruption reduces the safety margin.
Maintenance
Remove uneaten food and bottom waste, clean prefilters before flow falls, test ammonia and nitrite after changes, and perform regular temperature- and chemistry-matched water changes.
Overridable Warnings
Maintain locality records and never mix or release stock. This Australian native has regionally distinct populations and must not be collected, moved or released without lawful authority.

Welfare and risk

Main risk

Maintain locality records and never mix or release stock. This Australian native has regionally distinct populations and must not be collected, moved or released without lawful authority.

Use the adult housing and social plan in this profile, monitor body condition and behaviour, and correct measured water or compatibility problems early. An active native schooling fish that needs length and good oxygen—not a small “local” tank.

Non-overridable warning

Maintain locality records and never mix or release stock. This Australian native has regionally distinct populations and must not be collected, moved or released without lawful authority.

Sources

Source note

CURRENT