Identity and search names
- Common name
- Green neon tetra
- Scientific name
- Paracheirodon simulans
- Other names
- False neon tetra, Hyphessobrycon simulans
- Category
- Freshwater fish
- Group
- Tetras and characins
- Origin
- Upper Rio Negro and upper Orinoco blackwater systems of Brazil, Colombia and Venezuela
- Review outcome
- PASSED
Environment and housing
- Environment
- Freshwater
- Care level
- Intermediate
- Adult size
- Usually 1.5–2.5 cm
- Expected lifespan
- About 3–5 years
- Minimum housing
- At least 60 L for a shoal of 12 or more
- Temperature
- 24–28 °C
- pH
- 4.0–6.8
- Hardness or minerals
- Very soft to soft; breeding requires extremely low mineral content
- Salinity
- Freshwater
- Lighting
- Subdued lighting over a dark substrate
- Social structure
- Keep at least 12–15, preferably more
- Placement or swimming zone
- Middle water
- Temperament
- Very peaceful, shy and easily outcompeted
- Compatibility
- Use tiny peaceful blackwater fish; avoid mineral-demanding livebearers, large cichlids and boisterous feeders
- Habitat structure
- Mature shaded aquarium with dark substrate, leaf litter, wood, soft acidic water and open shoaling lanes
Feeding and nutrition
- Diet
- Micropredator taking minute crustaceans, insect larvae and very fine prepared foods
- Feeding frequency
- Offer tiny suspended meals once or twice daily and watch every fish feed
Breeding and reproduction
- Breeding or reproduction
- Egg scatterer requiring very soft acidic water and darkness; adults eat eggs and provide no care
- Parental care
- No parental care
System demands
- Filtration
- Use mature biological filtration sized for the full adult group and feeding load, with intake protection where juveniles, long fins or small fish are present. Provide steady turnover without preventing normal swimming or resting.
- Aeration
- Maintain strong surface gas exchange and stable dissolved oxygen. Increase aeration during warm weather, medication, transport recovery, breeding crowding or any ammonia or nitrite event.
- Maintenance
- Test ammonia, nitrite and nitrate, remove waste from feeding and shelter zones, and perform regular temperature- and chemistry-matched water changes before nitrate or dissolved organics accumulate.
Detailed husbandry
- Identity scope
- This profile applies to Paracheirodon simulans. It is smaller than neon and cardinal tetras, and its blue-green stripe extends farther toward the tail.
- Adult size and space
- Usually 1.5–2.5 cm. At least 60 L for a shoal of 12 or more. Plan around adult dimensions, activity, social structure, aggression and waste production rather than sale size.
- Social structure
- Keep at least 12–15, preferably more
- Placement or swimming zone
- Primary zone: Middle water. Keep that zone usable for movement, feeding and refuge.
- Feeding ecology
- Micropredator taking minute crustaceans, insect larvae and very fine prepared foods
- Feeding plan
- Offer tiny suspended meals once or twice daily and watch every fish feed
- Water stability
- Maintain 24–28 °C; pH 4.0–6.8; hardness/minerals: Very soft to soft; breeding requires extremely low mineral content. Stable oxygenation and nitrogen-cycle control matter more than chasing one exact number.
- Adult projected load
- Plan capacity for Keep at least 12–15, preferably more at the documented adult size (Usually 1.5–2.5 cm) in At least 60 L for a shoal of 12 or more. Include feeding intensity, territorial behaviour and breeding growth rather than counting sale-size juveniles.
- Filtration
- Use mature biological filtration sized for the full adult group and feeding load, with intake protection where juveniles, long fins or small fish are present. Provide steady turnover without preventing normal swimming or resting.
- Aeration
- Maintain strong surface gas exchange and stable dissolved oxygen. Increase aeration during warm weather, medication, transport recovery, breeding crowding or any ammonia or nitrite event.
- Maintenance
- Test ammonia, nitrite and nitrate, remove waste from feeding and shelter zones, and perform regular temperature- and chemistry-matched water changes before nitrate or dissolved organics accumulate.
- Habitat structure
- Mature shaded aquarium with dark substrate, leaf litter, wood, soft acidic water and open shoaling lanes
- Compatibility plan
- Use tiny peaceful blackwater fish; avoid mineral-demanding livebearers, large cichlids and boisterous feeders
- Breeding plan
- Egg scatterer requiring very soft acidic water and darkness; adults eat eggs and provide no care Parental care: No parental care.
- 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
- Maintain the stated adult space and social structure, verify feeding and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Its tiny size and extreme soft-water preference are routinely underestimated. Hard water and fast tankmates can cause chronic failure even when no acute disease is visible.
- 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
- Its tiny size and extreme soft-water preference are routinely underestimated. Hard water and fast tankmates can cause chronic failure even when no acute disease is visible.
- Overridable warnings
- Its tiny size and extreme soft-water preference are routinely underestimated. Hard water and fast tankmates can cause chronic failure even when no acute disease is visible. Any override must still preserve adult space, social welfare, stable chemistry, oxygen and filter capacity.
Welfare and risk
- Welfare checks
- Maintain the stated adult space and social structure, verify feeding and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Its tiny size and extreme soft-water preference are routinely underestimated. Hard water and fast tankmates can cause chronic failure even when no acute disease is visible.
- Main warning
- Its tiny size and extreme soft-water preference are routinely underestimated. Hard water and fast tankmates can cause chronic failure even when no acute disease is visible.
- Biosecurity
- 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.
Sources
Source note
Current identity or scope, husbandry, system-demand, welfare and Australian biosecurity evidence checked; active retired-source links removed; all AquaNexus wording is original.
- Eschmeyer’s Catalog of Fishes — Paracheirodon simulans — Current accepted-name, synonym, family and habitat check
- Eschmeyer’s Catalog of Fishes — Paracheirodon simulans — Accepted-name, synonym and taxonomic-placement cross-check
- Seriously Fish — Paracheirodon simulans — Adult scale, blackwater chemistry, shoaling, feeding and breeding evidence
- IUCN Red List search — Paracheirodon simulans — Conservation-status and wild-provenance cross-check
- PIRSA — South Australian noxious fish list — Current South Australian possession and trade restriction cross-check
- DAFF — importing live ornamental fish to Australia — Current Australian live-fish import pathway and permitted-species warning