HomeCompare fishMountain rainbowfish vs Blackfin pearlfish Mountain rainbowfish vs Blackfin pearlfish: can they live together? Verdict: Not recommendedThe Blackfin pearlfish is best kept in a species tank.The Blackfin pearlfish is aggressive towards other fish.Both are comfortable at 18–22°C (64–72°F).A pH of 6.5–7.0 suits both.Side by sideMountain rainbowfishBlackfin pearlfishAdult size10 cm (3.9 in)7 cm (2.8 in)Minimum tank210 L (55 US gal)55 L (15 US gal)Temperature18–22°C (64–72°F)18–24°C (64–75°F)pH6.5–7.26.0–7.0Hardness–5–12 dGH (89–214 ppm)TemperamentPeacefulAggressiveCommunity tankWith cautionNot suitableCare levelEasyModerateDietOmnivoreCarnivoreSpecies profilesMountain rainbowfishMelanotaenia monticolaBlackfin pearlfishAustrolebias nigripinnis