HomeFreshwater aquarium fishRainbowfish & killifishWerner's killifish Werner's killifish (Aplocheilus werneri) Scientific name: Aplocheilus werneri Meinken, 1966 The Werner's killifish (Aplocheilus werneri) is a freshwater fish of the family Aplocheilidae. Native range: Asia, endemic to Sri Lanka. BiologyInhabits small, shallow, slow-flowing, heavily shaded streams and rivulets with a silt or clay substrate. Feeds on insects and fish fry. 9 cm max TL. Not a seasonal killifish. Is easy to maintain in the aquarium.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameAplocheilus werneriFamilyAplocheilidae (Killifishes)OrderCyprinodontiformes (Live bearers, Killifishes and Rivulines)ClassActinopterygii (Ray-finned fishes)Maximum length7.0EnvironmentFreshwater; benthopelagic; non-migratoryClimateTropicalDistributionAsia: endemic to Sri Lanka.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: of no interest; aquarium: commercial More rainbowfish & killifishYellowbelly gudgeonAllomogurnda nesolepisKamaka rainbowfishMelanotaenia kamakaBanded rainbowfishMelanotaenia trifasciataFlagfishJordanella floridaeBluefin killifishLucania goodeiStriped panchaxAplocheilus lineatusSee 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