HomeFreshwater aquarium fishRainbowfish & killifishThreadfin rainbowfish Threadfin rainbowfish (Iriatherina werneri) Scientific name: Iriatherina werneri Meinken, 1974 The Threadfin rainbowfish (Iriatherina werneri) is a freshwater fish of the family Melanotaeniidae. In the aquarium it needs water at 26–30°C (79–86°F). Native range: Asia and Oceania, central-southern New Guinea and northern Australia. Threadfin rainbowfish care at a glanceTemperature26–30°C (79–86°F) BiologyDorsal spines (total): 7 - 10; Dorsal soft rays (total): 7; Anal spines: 1; Anal soft rays: 10 - 12Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameIriatherina werneriFamilyMelanotaeniidae (Rainbowfishes, blue eyes)OrderAtheriniformes (Silversides)ClassActinopterygii (Ray-finned fishes)Maximum length4.0Common length3.0EnvironmentFreshwater;; pH range: 6.0 - 8.0; dH range: 5 - 12 demersalClimateTropicalDistributionAsia and Oceania: central-southern New Guinea and northern Australia.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesAquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) More rainbowfish & killifishBanded rainbowfishMelanotaenia trifasciataYellowbelly gudgeonAllomogurnda nesolepisKamaka rainbowfishMelanotaenia kamakaJavanese ricefishOryzias javanicusFlagfishJordanella floridaeBluefin killifishLucania goodeiSee all rainbowfish & killifish SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026