AquaNexus verified profile
Threadfin rainbowfish
Iriatherina werneri
Threadfin rainbowfish is Iriatherina werneri, a delicate New Guinea and northern Australian shoaling fish requiring twelve or more, minute foods and calm planted water.
Outcome: PASSED Permanent ID: 678
Profile overview
- Scientific Name
- Iriatherina werneri
- Category
- Freshwater fish
- Subgroup
- Rainbowfish and blue-eyes
- Environment
- Freshwater aquarium
- Origin
- Slow, plant-rich wetlands and streams of southern New Guinea and northern Australia
- Care
- Intermediate
- Adult Size
- About 4–5 cm total length; mature males carry very long delicate fin rays
- Lifespan
- 3–5 years
- Tank
- At least 90 L for twelve or more, with broad surface area and calm feeding zones
- Temp
- 24–29 °C
- pH
- 5.5–7.5
- Hardness
- Soft to moderately hard; avoid abrupt mineral changes
- Salinity
- Freshwater; no routine salt addition
- Lighting
- Normal aquarium lighting
- Placement
- Upper and mid water
- Diet
- Tiny zooplankton, insects and other minute prey, supplemented with very fine prepared foods
- Filtration
- Use mature biological filtration with effective mechanical solids capture and turnover matched to the species’ natural flow needs. Protect intakes, preserve established media during cleaning and keep ammonia and nitrite at zero.
- Aeration
- Maintain continuous surface agitation and dependable dissolved oxygen across the whole aquarium. Increase oxygen reserve in warm water, strong-current systems, dense groups, medication periods and power interruptions.
- Maintenance
- Observe feeding, respiration, body condition and social behaviour daily; test nitrogen waste and key chemistry on a schedule; clean mechanical media before trapped waste decomposes; and perform regular temperature- and chemistry-matched water changes.
- Welfare
- Maintain the stated adult space and social structure, verify feeding, and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. Threadfin rainbowfish often starve in apparently peaceful communities because their mouths are tiny and feeding is slow. Long male fins are also vulnerable to nipping and strong current.
- 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.
- Review Status
- PASSED
- Source Status
- CURRENT — accepted identity or explicitly bounded species profile; husbandry, welfare, sources and Australian/South Australian biosecurity rechecked. CURRENT
App-ready care, welfare and biosecurity details
Identity Scope
Single-species profile for Iriatherina werneri. Preserve permanent AquaNexus ID 678, slug threadfin-rainbowfish and route /species/threadfin-rainbowfish/; retain former combinations, locality labels and trade names only as searchable aliases.
Adult Size And Space
Expected adult size: About 4–5 cm total length; mature males carry very long delicate fin rays. Minimum permanent housing: At least 90 L for twelve or more, with broad surface area and calm feeding zones. Plan around adult dimensions, activity, social structure, aggression, oxygen demand and waste production rather than sale size.
Social Structure
Keep twelve or more with multiple males and females so displays are distributed without isolating timid fish
Swimming Zone
Primary zone: Upper and mid water. Keep that zone usable for movement, feeding, refuge and escape.
Feeding Ecology
Tiny zooplankton, insects and other minute prey, supplemented with very fine prepared foods
Feeding Plan
Feed tiny floating or slowly sinking foods in several places once or twice daily; confirm every fish eats before faster tankmates clear the food
Water Stability
Maintain 24–29 °C; pH 5.5–7.5; hardness or minerals: Soft to moderately hard; avoid abrupt mineral changes; salinity: Freshwater; no routine salt addition. Stable oxygenation and nitrogen-cycle control matter more than chasing one exact value.
Habitat Structure
Mature planted aquarium with fine-leaved plants, floating cover, gentle flow, open display space and a secure lid
Compatibility Plan
Use only calm small fish that cannot nip the extended fins or outcompete this species for minute food
Breeding Plan
Plant-spawning rainbowfish depositing adhesive eggs over fine vegetation or spawning mops; no parental care Parental care: No parental care; adults may eat eggs and fry.
Quarantine
Quarantine new fish in a separate cycled aquarium with dedicated equipment. Match temperature and mineral chemistry gradually, confirm feeding, respiration, skin, fins and waste, 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. Threadfin rainbowfish often starve in apparently peaceful communities because their mouths are tiny and feeding is slow. Long male fins are also vulnerable to nipping and strong current.
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
Threadfin rainbowfish often starve in apparently peaceful communities because their mouths are tiny and feeding is slow. Long male fins are also vulnerable to nipping and strong current.
Adult Projected Load
Plan filtration and stocking for the full adult size (About 4–5 cm total length; mature males carry very long delicate fin rays), the complete social group and peak feeding waste, not the current shop size. Permanent housing remains At least 90 L for twelve or more, with broad surface area and calm feeding zones.
Filtration
Use mature biological filtration with effective mechanical solids capture and turnover matched to the species’ natural flow needs. Protect intakes, preserve established media during cleaning and keep ammonia and nitrite at zero.
Aeration
Maintain continuous surface agitation and dependable dissolved oxygen across the whole aquarium. Increase oxygen reserve in warm water, strong-current systems, dense groups, medication periods and power interruptions.
Maintenance
Observe feeding, respiration, body condition and social behaviour daily; test nitrogen waste and key chemistry on a schedule; clean mechanical media before trapped waste decomposes; and perform regular temperature- and chemistry-matched water changes.
Overridable Warnings
Warnings are decision support, not permission to ignore welfare limits. Override only with specimen-specific evidence, equivalent risk controls and a recorded reason; never override legal, biosecurity, provenance or no-release requirements.
Sources and review basis
- Eschmeyer’s Catalog of Fishes — Iriatherina werneri: Taxonomy — accepted name, former combinations, synonyms and identity cross-check
- U.S. Fish and Wildlife Service — Iriatherina werneri: Identity and distribution — independent species account and provenance cross-check
- IUCN Red List search — Iriatherina werneri: Conservation and provenance — wild-status, locality and collection-risk cross-check
- PIRSA — South Australian noxious fish list: Australian biosecurity — current South Australian possession, trade and movement restrictions
- DAFF — importing live ornamental fish to Australia: Australian biosecurity — national live-fish import pathways and permitted-species warning
AquaNexus uses original editorial synthesis. Exact import, possession, movement and disposal requirements must be rechecked with the current authority before acquisition or transfer.