HomeFreshwater aquarium fishRainbowfish & killifishBlackfin pearlfish Blackfin pearlfish (Austrolebias nigripinnis) Scientific name: Austrolebias nigripinnis Regan, 1912 The Blackfin pearlfish (Austrolebias nigripinnis) is a freshwater fish of the family Rivulidae that grows to about 7 cm (2.8 in). It is moderate to keep and aggressive, is best kept in a species tank and needs a tank of at least 55 L (15 US gal), water at 18–24°C (64–75°F) and a pH of 6.0–7.0. Native range: South America, Lower Paran? and Uruguay River basins. Blackfin pearlfish care at a glanceCare levelModerateTemperamentAggressiveCommunity tankNot suitableAdult size7 cm (2.8 in)Minimum tank55 L (15 US gal)Temperature18–24°C (64–75°F)pH6.0–7.0Hardness5–12 dGH (89–214 ppm)DietCarnivore. Accepts flakes, frozen foods and live foods. BiologyFeeds on worms, crustaceans and insects. Bottom spawner, 2-4 months incubation. Is easy to maintain in the aquarium.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameAustrolebias nigripinnisFamilyRivulidae (Rivulines)OrderCyprinodontiformes (Live bearers, Killifishes and Rivulines)ClassActinopterygii (Ray-finned fishes)Maximum length7.0Common length4.5EnvironmentFreshwater;; pH range: 6.0 - 7.0; dH range: 5 - 12 benthopelagic; non-migratoryClimateSubtropicalDistributionSouth America: Lower Paran? and Uruguay River basins.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesAquarium: commercialResilienceHigh, minimum population doubling time less than 15 months (Tmax More rainbowfish & killifishForktail rainbowfishPseudomugil furcatusDwarf rainbowfishMelanotaenia praecoxLake Kutubu rainbowfishMelanotaenia lacustrisTami River rainbowfishGlossolepis pseudoincisusRed rainbowfishGlossolepis incisusJavanese ricefishOryzias javanicusSee all rainbowfish & killifish Can it live with...?Blackfin pearlfish and Banded rainbowfishBlackfin pearlfish and Dwarf rainbowfishBlackfin pearlfish and Forktail rainbowfishBlackfin pearlfish and Javanese ricefishBlackfin pearlfish and Kamaka rainbowfishBlackfin pearlfish and Lake Kutubu rainbowfishBlackfin pearlfish and Mountain rainbowfishBlackfin pearlfish and Murray river rainbowfishBlackfin pearlfish and Red rainbowfishBlackfin pearlfish and Tami River rainbowfishBlackfin pearlfish 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