HomeFreshwater aquarium fishRainbowfish & killifishMountain rainbowfish Mountain rainbowfish (Melanotaenia monticola) Scientific name: Melanotaenia monticola Allen, 1980 The Mountain rainbowfish (Melanotaenia monticola) is a freshwater fish of the family Melanotaeniidae that grows to about 10 cm (3.9 in). It is easy to keep and peaceful, needs carefully chosen tank mates and needs a tank of at least 210 L (55 US gal), water at 18–22°C (64–72°F) and a pH of 6.5–7.2. Native range: New Guinea, Southern Highlands of Papua New Guinea between Mendi and Lake Kutubu, in the Purari River system. Mountain rainbowfish care at a glanceCare levelEasyTemperamentPeacefulCommunity tankWith cautionAdult size10 cm (3.9 in)Minimum tank210 L (55 US gal)Temperature18–22°C (64–72°F)pH6.5–7.2DietOmnivore. Accepts flakes, frozen foods and live foods. BiologyDorsal spines (total): 5 - 6; Dorsal soft rays (total): 15-17; Anal spines: 1; Anal soft rays: 18 - 21Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameMelanotaenia monticolaFamilyMelanotaeniidae (Rainbowfishes, blue eyes)OrderAtheriniformes (Silversides)ClassActinopterygii (Ray-finned fishes)Maximum length8.0EnvironmentFreshwater; benthopelagicClimateTropicalDistributionOceania: Southern Highlands of Papua New Guinea between Mendi and Lake Kutubu, in the Purari River system, Omei Creek, 15 km south of Mendi and streams near Pimaga (13 km southeast of Lake Kutubu).Conservation status (IUCN)Data deficient (DD)Threat to humansHarmlessUsesAquarium: commercialResilienceMedium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.) More rainbowfish & killifishLake Kutubu rainbowfishMelanotaenia lacustrisDwarf rainbowfishMelanotaenia praecoxTami River rainbowfishGlossolepis pseudoincisusRed rainbowfishGlossolepis incisusForktail rainbowfishPseudomugil furcatusBlackfin pearlfishAustrolebias nigripinnisSee all rainbowfish & killifish Can it live with...?Mountain rainbowfish and Banded rainbowfishMountain rainbowfish and Blackfin pearlfishMountain rainbowfish and Dwarf rainbowfishMountain rainbowfish and Forktail rainbowfishMountain rainbowfish and Javanese ricefishMountain rainbowfish and Kamaka rainbowfishMountain rainbowfish and Lake Kutubu rainbowfishMountain rainbowfish and Murray river rainbowfishMountain rainbowfish and Red rainbowfishMountain rainbowfish and Tami River rainbowfishMountain rainbowfish and Yellowbelly 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