Blackline Rasbora Tank Mates

• Adolf's Cory✅ Compatible
  Peaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
  • Both are peaceful, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Adolf's Cory in a shoal of 6+ or it gets stressed and nippy.
• Agassiz's Corydoras✅ Compatible
  Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
• Blood Red Tiger Pleco✅ Compatible
  Peaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Bloodfin Tetra✅ Compatible
  Peaceful · 5.5 cm · Easy care · 18–28 °C (64–82 °F)
  • Compatible on the things that matter: shared water near 22–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
• Butterfly Hillstream Loach✅ Compatible
  Peaceful · 6 cm · Hard care · 18–24 °C (64–75 °F)
  • Compatible on the things that matter: shared water near 22–24 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Corydoras Catfish✅ Compatible
  Peaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
  • Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Corydoras Catfish in a shoal of 6+ or it gets stressed and nippy.
• Diamond Tetra✅ Compatible
  Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Diamond Tetra in a shoal of 6+ or it gets stressed and nippy.
• Duplicareus Corydoras✅ Compatible
  Peaceful · 5.5 cm · Medium care · 23–27 °C (73–81 °F)
  • Both are peaceful, and their water overlaps around 23–27 °C — no size, zone or temperament conflicts.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Duplicareus Corydoras in a shoal of 6+ or it gets stressed and nippy.
• Elegant Cory✅ Compatible
  Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
  • Compatible on the things that matter: shared water near 22–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Elegant Cory in a shoal of 6+ or it gets stressed and nippy.
• False Julii Corydoras✅ Compatible
  Peaceful · 6 cm · Easy care · 22–26 °C (72–79 °F)
  • Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep False Julii Corydoras in a shoal of 6+ or it gets stressed and nippy.
• German Blue Ram✅ Compatible
  Peaceful · 6 cm · Hard care · 27–30 °C (81–86 °F)
  • Compatible on the things that matter: shared water near 27–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Glass Bloodfin Tetra✅ Compatible
  Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Glass Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
• Guppy✅ Compatible
  Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Hillstream Loach✅ Compatible
  Peaceful · 6 cm · Hard care · 20–24 °C (68–75 °F)
  • Compatible on the things that matter: shared water near 22–24 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Narcissus II Cory✅ Compatible
  Peaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
  • Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Narcissus II Cory in a shoal of 6+ or it gets stressed and nippy.
• Neon Dwarf Rainbowfish✅ Compatible
  Peaceful · 6 cm · Easy care · 23–27 °C (73–81 °F)
  • Both are peaceful, and their water overlaps around 23–27 °C — no size, zone or temperament conflicts.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Neon Dwarf Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
• Panda Loach✅ Compatible
  Peaceful · 6 cm · Hard care · 18–23 °C (64–73 °F)
  • Compatible on the things that matter: shared water near 22–23 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Pearl Danio✅ Compatible
  Peaceful · 6 cm · Easy care · 20–25 °C (68–77 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
• Platy✅ Compatible
  Peaceful · 6 cm · Easy care · 21–28 °C (70–82 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Rust Corydoras✅ Compatible
  Peaceful · 5.5 cm · Easy care · 23–27 °C (73–81 °F)
  • Both are peaceful, and their water overlaps around 23–27 °C — no size, zone or temperament conflicts.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Rust Corydoras in a shoal of 6+ or it gets stressed and nippy.
• Samurai Gourami✅ Compatible
  Peaceful · 6 cm · Hard care · 24–28 °C (75–82 °F)
  • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Slate Corydoras✅ Compatible
  Peaceful · 6 cm · Medium care · 23–28 °C (73–82 °F)
  • Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Slate Corydoras in a shoal of 6+ or it gets stressed and nippy.
• Spotfin Corydoras✅ Compatible
  Peaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
  • Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Spotfin Corydoras in a shoal of 6+ or it gets stressed and nippy.
• Sterbai Corydoras✅ Compatible
  Peaceful · 6.5 cm · Medium care · 24–30 °C (75–86 °F)
  • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
• Ash Lipped Apisto⚠️ With caution
  Semi-aggressive · 7 cm · Hard care · 24–29 °C (75–84 °F)
  • Ash Lipped Apisto is semi-aggressive and may chase or nip the smaller Blackline Rasbora — plant heavily and break up sight lines.
  • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Banded Dwarf Cichlid⚠️ With caution
  Semi-aggressive · 7 cm · Medium care · 24–30 °C (75–86 °F)
  • Banded Dwarf Cichlid and Blackline Rasbora are close in size, but the semi-aggressive one tends to dominate — add blackline rasbora in a group to spread the pressure.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Betta⚠️ With caution
  Semi-aggressive · 6.5 cm · Easy care · 24–28 °C (75–82 °F)
  • Expect Betta to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Black Ruby Barb⚠️ With caution
  Semi-aggressive · 6 cm · Easy care · 22–26 °C (72–79 °F)
  • Black Ruby Barb is semi-aggressive and may chase or nip the smaller Blackline Rasbora — plant heavily and break up sight lines.
  • Your 75 L tank is below the ~100 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Black Ruby Barb in a shoal of 6+ or it gets stressed and nippy.
• Black Skirt Tetra⚠️ With caution
  Semi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
  • Expect Black Skirt Tetra to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
• Bleeding Heart Tetra⚠️ With caution
  Semi-aggressive · 7 cm · Medium care · 23–28 °C (73–82 °F)
  • Expect Bleeding Heart Tetra to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Bleeding Heart Tetra in a shoal of 6+ or it gets stressed and nippy.
• Bright Diamond Tetra⚠️ With caution
  Peaceful · 7 cm · Hard care · 24–28 °C (75–82 °F)
  • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Bright Diamond Tetra in a shoal of 8+ or it gets stressed and nippy.
• Colombian Tetra⚠️ With caution
  Semi-aggressive · 6.5 cm · Easy care · 24–28 °C (75–82 °F)
  • Expect Colombian Tetra to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Your 75 L tank is below the ~114 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Colombian Tetra in a shoal of 6+ or it gets stressed and nippy.
• Desert Goby⚠️ With caution
  Semi-aggressive · 6 cm · Easy care · 18–28 °C (64–82 °F)
  • Desert Goby is semi-aggressive and may chase or nip the smaller Blackline Rasbora — plant heavily and break up sight lines.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Dwarf Chain Loach⚠️ With caution
  Peaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
  • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Dwarf Chain Loach in a shoal of 6+ or it gets stressed and nippy.
• Eastern Betta⚠️ With caution
  Semi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
  • Expect Eastern Betta to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• GloFish Tetra⚠️ With caution
  Semi-aggressive · 6 cm · Easy care · 21–28 °C (70–82 °F)
  • Expect GloFish Tetra to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep GloFish Tetra in a shoal of 6+ or it gets stressed and nippy.
• Odessa Barb⚠️ With caution
  Semi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
  • Odessa Barb is semi-aggressive and may chase or nip the smaller Blackline Rasbora — plant heavily and break up sight lines.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
• Peaceful Betta⚠️ With caution
  Semi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
  • Expect Peaceful Betta to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Smaragd Betta⚠️ With caution
  Aggressive · 6 cm · Medium care · 23–28 °C (73–82 °F)
  • Smaragd Betta and Blackline Rasbora are close in size, but the aggressive one tends to dominate — add blackline rasbora in a group to spread the pressure.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Three-striped Dwarf Cichlid⚠️ With caution
  Semi-aggressive · 6 cm · Medium care · 23–29 °C (73–84 °F)
  • Expect Three-striped Dwarf Cichlid to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Alligator Gar⛔ Not recommended
  Aggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
  • Size gap is too large (250 vs 6 cm): Alligator Gar will treat Blackline Rasbora as food.
  • Alligator Gar is aggressive and may chase or nip the smaller Blackline Rasbora — plant heavily and break up sight lines.
  • Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Clown Knifefish⛔ Not recommended
  Aggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
  • Size gap is too large (90 vs 6 cm): Clown Knifefish will treat Blackline Rasbora as food.
  • Expect Clown Knifefish to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Fire Eel⛔ Not recommended
  Semi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
  • Blackline Rasbora is bite-sized to a 100 cm predatory fire eel — it will be eaten.
  • Fire Eel is semi-aggressive and may chase or nip the smaller Blackline Rasbora — plant heavily and break up sight lines.
  • Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Koi⛔ Not recommended
  Peaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
  • Koi (90 cm) is big enough to swallow the 6 cm Blackline Rasbora whole.
  • Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Redtail Catfish⛔ Not recommended
  Aggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
  • Blackline Rasbora is bite-sized to a 120 cm predatory redtail catfish — it will be eaten.
  • Expect Redtail Catfish to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Spotted Gar⛔ Not recommended
  Aggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
  • Size gap is too large (90 vs 6 cm): Spotted Gar will treat Blackline Rasbora as food.
  • Expect Spotted Gar to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Wels Catfish⛔ Not recommended
  Aggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
  • Blackline Rasbora is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
  • Expect Wels Catfish to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Your 75 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
• Wolf Cichlid⛔ Not recommended
  Aggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
  • Blackline Rasbora is bite-sized to a 72 cm predatory wolf cichlid — it will be eaten.
  • Wolf Cichlid is aggressive and may chase or nip the smaller Blackline Rasbora — plant heavily and break up sight lines.
  • Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
  • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.

Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.