HomeFreshwater aquarium fishRainbowfish & killifishLake Kutubu rainbowfish Lake Kutubu rainbowfish (Melanotaenia lacustris) Scientific name: Melanotaenia lacustris Munro, 1964 The Lake Kutubu rainbowfish (Melanotaenia lacustris) is a freshwater fish of the family Melanotaeniidae that grows to about 10 cm (3.9 in). It is easy to keep and peaceful, suits community aquariums and needs a tank of at least 210 L (55 US gal), water at 20–24°C (68–75°F) and a pH of 7.0–8.0. Native range: Se. Asian Islands, Lake Katubu, southern Papua New Guinea. Lake Kutubu rainbowfish care at a glanceCare levelEasyTemperamentPeacefulCommunity tankGoodAdult size10 cm (3.9 in)Minimum tank210 L (55 US gal)Temperature20–24°C (68–75°F)pH7.0–8.0Hardness9–12 dGH (161–214 ppm)DietOmnivore. Accepts flakes, frozen foods and live foods. BiologyDorsal spines (total): 5 - 7; Dorsal soft rays (total): 11-14; Anal spines: 1; Anal soft rays: 17 - 21Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameMelanotaenia lacustrisFamilyMelanotaeniidae (Rainbowfishes, blue eyes)OrderAtheriniformes (Silversides)ClassActinopterygii (Ray-finned fishes)Maximum length10.0EnvironmentFreshwater;; pH range: 7.0 - 8.0; dH range: 9 - 12 benthopelagicClimateTropicalDistributionOceania: known only from Lake Kutubu and its outlet, the Soro River, in the Kikori River drainage of the Southern Highlands, Papua New Guinea.Conservation status (IUCN)Vulnerable (VU) (A1ac)Threat to humansHarmlessUsesGamefish: yes; aquarium: commercialResilienceMedium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.) More rainbowfish & killifishTami River rainbowfishGlossolepis pseudoincisusDwarf rainbowfishMelanotaenia praecoxRed rainbowfishGlossolepis incisusForktail rainbowfishPseudomugil furcatusBlackfin pearlfishAustrolebias nigripinnisJavanese ricefishOryzias javanicusSee all rainbowfish & killifish Can it live with...?Lake Kutubu rainbowfish and Banded rainbowfishLake Kutubu rainbowfish and Black ghostLake Kutubu rainbowfish and Black sharkminnowLake Kutubu rainbowfish and Blackfin pearlfishLake Kutubu rainbowfish and Bleeding-heart tetraLake Kutubu rainbowfish and Bloodfin tetraLake Kutubu rainbowfish and Bluespotted corydorasLake Kutubu rainbowfish and Brilliant rasboraLake Kutubu rainbowfish and Chinese suckerLake Kutubu rainbowfish and Clown barbLake Kutubu rainbowfish and Clown loachLake Kutubu rainbowfish and Clown rasboraLake Kutubu rainbowfish and Crescent bettaLake Kutubu rainbowfish and Dwarf rainbowfishLake Kutubu rainbowfish and Eel LoachLake Kutubu rainbowfish and Forktail rainbowfishLake Kutubu rainbowfish and Gangetic leaffishLake Kutubu rainbowfish and Garnet tetraLake Kutubu rainbowfish and Glass catfishLake Kutubu rainbowfish and Glowlight tetraLake Kutubu rainbowfish and Goldeneye cichlidLake Kutubu rainbowfish and Head-and-taillight tetraLake Kutubu rainbowfish and Indian glassy fishLake Kutubu rainbowfish and Javanese ricefishLake Kutubu rainbowfish and Kamaka rainbowfishLake Kutubu rainbowfish and Leopard corydorasLake Kutubu rainbowfish and MosquitofishLake Kutubu rainbowfish and Mountain rainbowfishLake Kutubu rainbowfish and Murray river rainbowfishLake Kutubu rainbowfish and Northern trout gudgeon 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