🐟 Threadfin Rainbowfish Iriatherina werneri

The Threadfin Rainbowfish (Iriatherina werneri) is a moderate-care, peaceful species from Northern Australia and New Guinea. Adults reach roughly 1.6", so plan on a minimum tank of 15 gallons. Keep the water between 72–86°F with a pH of 5.5–7.5. This is a schooling fish — keep a group of at least 8 so it feels secure and colors up. Its long fins make it a target for known fin-nippers. As an omnivore, it does best on a varied diet appropriate to its feeding style.

At a glance

Good tankmates for Threadfin Rainbowfish

Neon TetraCardinal TetraRummynose TetraGuppyEndler's LivebearerPlatyGerman Blue RamBolivian RamApistogrammaHarlequin RasboraChili RasboraCherry BarbWhite Cloud MinnowDwarf GouramiBronze CoryPanda CoryOtocinclusAmano ShrimpNerite SnailMystery SnailMarble HatchetfishEmber TetraBlack Neon TetraLemon TetraGlowlight TetraCongo TetraDiamond TetraEmperor TetraX-Ray TetraGreen Neon TetraCelestial Pearl DanioLambchop RasboraScissortail RasboraGlowlight DanioCheckerboard BarbNeon Dwarf RainbowfishCelebes RainbowfishHoney GouramiSparkling GouramiChocolate GouramiRainbow CichlidPygmy CorySterbai CoryJulii CoryUpside-Down CatfishZebra LoachHillstream LoachClown PlecoLeast KillifishRosy Red MinnowGhost ShrimpBamboo ShrimpCrystal Red ShrimpAssassin SnailRamshorn SnailMalaysian Trumpet SnailRabbit SnailGold TetraPenguin TetraFlame TetraBleeding Heart TetraGalaxy RasboraPhoenix RasboraEmerald Eye RasboraAxelrod's RasboraGold Ring DanioRuby BarbMelon BarbForktail Blue-eyeLicorice GouramiCroaking GouramiThick-Lipped GouramiPeaceful BettaStrawberry BettaGolden RamFlag AcaraYellow Dwarf CichlidAgassiz's Dwarf CichlidHongsloi CichlidCheckerboard CichlidEmerald CoryAlbino CoryThree-Striped CoryAdolfo's CoryHabrosus CoryZebra OtoDwarf Chain LoachZebra Pleco (L046)Bumblebee ShrimpLyretail KillifishClown KillifishHigh-Fin PlatyBalloon MollyIndian Glassfish

Avoid these tankmates

AngelfishConvict CichlidOscarPictus CatfishJack DempseyGreen TerrorTexas CichlidDemasoni CichlidAuratus CichlidFrontosaChinese Algae EaterRed Tail SharkFigure-8 PufferBlack Ghost KnifefishAfrican Butterfly FishRopefishSenegal BichirGolden Wonder KillifishBucktooth TetraBanjar Red CichlidSalvini CichlidMidas CichlidFlowerhornRed Zebra CichlidVenustus CichlidLivingstonii CichlidCompressed CichlidCalvus CichlidTropheus Duboisi

See the full tankmate guide for Threadfin Rainbowfish →