HomeFreshwater aquarium fishRainbowfish & killifishRedtail notho Redtail notho (Nothobranchius guentheri) Scientific name: Nothobranchius guentheri Pfeffer, 1893 The Redtail notho (Nothobranchius guentheri) is a freshwater fish of the family Nothobranchiidae that grows to about 5.5 cm (2.2 in). It is difficult to keep and aggressive, is best kept in a species tank and needs a tank of at least 40 L (11 US gal), water at 22–25°C (72–77°F) and a pH of 6.0–7.0. Native range: Africa, Endemic to the island of Zanzibar, eastern Tanzania. Redtail notho care at a glanceCare levelDifficultTemperamentAggressiveCommunity tankNot suitableAdult size5.5 cm (2.2 in)Minimum tank40 L (11 US gal)Temperature22–25°C (72–77°F)pH6.0–7.0Hardness4–10 dGH (71–178 ppm)DietOmnivore. Accepts flakes, frozen foods and live foods. BiologyFound in seasonal pools and streams. Used for biological control of mosquitoes. Quite popular with aquarists. One of the so called 'annual fishes' which has eggs that can withstand seasonal droughts. Bottom spawner, 3-4 months incubation. Difficult to maintain in an aquarium.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameNothobranchius guentheriFamilyNothobranchiidae (African rivulines)OrderCyprinodontiformes (Live bearers, Killifishes and Rivulines)ClassActinopterygii (Ray-finned fishes)Maximum length5.5EnvironmentFreshwater;; pH range: 6.0 - 7.0; dH range: 4 - 10 benthopelagic; non-migratoryClimateTropicalDistributionAfrica: endemic to the island of Zanzibar, eastern Tanzania.Conservation status (IUCN)Least Concern (LC)Threat to humansHarmlessUsesFisheries: of no interest; aquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (tm= 0.12-0.15; tmax More rainbowfish & killifishStriped panchaxAplocheilus lineatusArgentine pearlfishAustrolebias bellottiiBluefin killifishLucania goodeiFlagfishJordanella floridaeKamaka rainbowfishMelanotaenia kamakaYellowbelly gudgeonAllomogurnda nesolepisSee all rainbowfish & killifish SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0. Aquarium care parameters compiled, checked and converted to metric and imperial units by Guppies.za.net.Last updated 28 September 2026