Photo: Rahul Gautam (CC BY 4.0) — via Wikimedia Commons
Mascara Barb (Dawkinsia assimilis)
A bold, fast-moving schooling barb from India's Western Ghats with striking red fins and a distinctive black eye-stripe that inspired its name.
Will it live with a Mascara Barb?
We compare each fish against your mascara barb on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Bearded Corydoras✅ CompatiblePeaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
- Compatible on the things that matter: shared water near 20–24 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Bearded Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Boesemani Rainbowfish✅ CompatiblePeaceful · 11 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–25 °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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Boesemani Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Bristlenose Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
- Compatible on the things that matter: shared water near 23–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Clown Rasbora✅ CompatiblePeaceful · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–25 °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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Clown Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Convict Cichlid✅ CompatibleAggressive · 10 cm · Easy care · 21–28 °C (70–82 °F)
- Compatible on the things that matter: shared water near 21–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Giant Betta✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Compatible on the things that matter: shared water near 24–25 °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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Giant Danio✅ CompatiblePeaceful · 10 cm · Easy care · 20–27 °C (68–81 °F)
- Both are peaceful, and their water overlaps around 20–25 °C — no size, zone or temperament conflicts.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Giant Danio in a shoal of 6+ or it gets stressed and nippy.
- Giant Kuhli Loach✅ CompatiblePeaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
- Both are peaceful, and their water overlaps around 24–25 °C — no size, zone or temperament conflicts.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Golden Wonder Killifish✅ CompatibleSemi-aggressive · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keyhole Cichlid✅ CompatiblePeaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful, and their water overlaps around 22–25 °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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Kribensis✅ CompatibleSemi-aggressive · 10 cm · Easy care · 24–27 °C (75–81 °F)
- Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Kuhli Loach✅ CompatiblePeaceful · 10 cm · Easy care · 24–30 °C (75–86 °F)
- Compatible on the things that matter: shared water near 24–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Marbled Hoplo✅ CompatiblePeaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Molly✅ CompatiblePeaceful · 10 cm · Easy care · 23–28 °C (73–82 °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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Murray River Rainbowfish✅ CompatiblePeaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
- Both are peaceful, and their water overlaps around 20–25 °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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Murray River Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Paradise Fish✅ CompatibleAggressive · 10 cm · Medium care · 16–26 °C (61–79 °F)
- Compatible on the things that matter: shared water near 20–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Pearl Gourami✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–25 °C — no size, zone or temperament conflicts.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Porthole Catfish✅ CompatiblePeaceful · 10 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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Rubber Lip Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 20–26 °C (68–79 °F)
- Both are peaceful, and their water overlaps around 20–25 °C — no size, zone or temperament conflicts.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Spotted Rubbernose Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Striped Eel Loach✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Tiger Betta✅ CompatibleSemi-aggressive · 11 cm · Hard care · 22–27 °C (72–81 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 22–25 °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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Topaz Cichlid✅ CompatibleSemi-aggressive · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here; 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 Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Upside-down Catfish✅ CompatiblePeaceful · 10 cm · Easy care · 22–26 °C (72–79 °F)
- Both are peaceful, and their water overlaps around 22–25 °C — no size, zone or temperament conflicts.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Arrowhead Puffer⚠️ With cautionAggressive · 12 cm · Hard care · 23–28 °C (73–82 °F)
- Arrowhead Puffer and Mascara Barb are close in size, but the aggressive one tends to dominate — add mascara barb in a group to spread the pressure.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Auratus Cichlid⚠️ With cautionAggressive · 11 cm · Medium care · 23–28 °C (73–82 °F)
- Different pH ranges (6–7.5 vs 7.6–8.8); doable if you sit in the shared band, but not ideal long-term.
- Auratus Cichlid is a notorious fin-nipper — even though Mascara Barb is larger, an active shoal will harass its trailing fins. Only safe in a full group of 6+ with plenty of cover.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Auratus Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Banded Gourami⚠️ With cautionSemi-aggressive · 12 cm · Easy care · 22–28 °C (72–82 °F)
- Banded Gourami is semi-aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Blue Gourami⚠️ With cautionSemi-aggressive · 13 cm · Easy care · 22–28 °C (72–82 °F)
- Blue Gourami and Mascara Barb are close in size, but the semi-aggressive one tends to dominate — add mascara barb in a group to spread the pressure.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Bucktooth Tetra⚠️ With cautionAggressive · 12 cm · Medium care · 23–28 °C (73–82 °F)
- Expect Bucktooth Tetra to harass Mascara Barb at times; give dense cover and watch them at feeding.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Bucktooth Tetra in a shoal of 8+ or it gets stressed and nippy.
- Calvus Cichlid⚠️ With cautionSemi-aggressive · 14 cm · Medium care · 24–27 °C (75–81 °F)
- pH preferences only just meet (Mascara Barb 6–7.5 vs Calvus Cichlid 7.8–9) — target the overlap and acclimate slowly.
- Calvus Cichlid is semi-aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Cupid Cichlid⚠️ With cautionSemi-aggressive · 12 cm · Medium care · 24–29 °C (75–84 °F)
- Cupid Cichlid is semi-aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Ice Blue Cichlid⚠️ With cautionAggressive · 12 cm · Medium care · 24–28 °C (75–82 °F)
- pH preferences only just meet (Mascara Barb 6–7.5 vs Ice Blue Cichlid 7.6–8.6) — target the overlap and acclimate slowly.
- Ice Blue Cichlid and Mascara Barb are close in size, but the aggressive one tends to dominate — add mascara barb in a group to spread the pressure.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Pictus Catfish⚠️ With cautionSemi-aggressive · 12 cm · Medium care · 22–27 °C (72–81 °F)
- Pictus Catfish is semi-aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Your 200 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Polka-dot Loach⚠️ With cautionSemi-aggressive · 13 cm · Medium care · 24–28 °C (75–82 °F)
- Polka-dot Loach and Mascara Barb are close in size, but the semi-aggressive one tends to dominate — add mascara barb in a group to spread the pressure.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Powder Blue Cichlid⚠️ With cautionSemi-aggressive · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Powder Blue Cichlid and Mascara Barb are close in size, but the semi-aggressive one tends to dominate — add mascara barb in a group to spread the pressure.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Powder Blue Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Rainbow Cichlid⚠️ With cautionSemi-aggressive · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Rainbow Cichlid and Mascara Barb are close in size, but the semi-aggressive one tends to dominate — add mascara barb in a group to spread the pressure.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Red Zebra Cichlid⚠️ With cautionAggressive · 13 cm · Medium care · 23–28 °C (73–82 °F)
- pH preferences only just meet (Mascara Barb 6–7.5 vs Red Zebra Cichlid 7.6–8.6) — target the overlap and acclimate slowly.
- Red Zebra Cichlid and Mascara Barb are close in size, but the aggressive one tends to dominate — add mascara barb in a group to spread the pressure.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep Red Zebra Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Swordtail⚠️ With cautionSemi-aggressive · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Swordtail is semi-aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- T-bar Cichlid⚠️ With cautionSemi-aggressive · 12 cm · Medium care · 22–28 °C (72–82 °F)
- Expect T-bar Cichlid to harass Mascara Barb at times; give dense cover and watch them at feeding.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- White Spotted Cichlid⚠️ With cautionAggressive · 12 cm · Hard care · 24–28 °C (75–82 °F)
- Different pH ranges (6–7.5 vs 7.8–9); doable if you sit in the shared band, but not ideal long-term.
- Expect White Spotted Cichlid to harass Mascara Barb at times; give dense cover and watch them at feeding.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Keep White Spotted Cichlid in a shoal of 8+ or it gets stressed and nippy.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Mascara Barb is bite-sized to a 250 cm predatory alligator gar — it will be eaten.
- Expect Alligator Gar to harass Mascara Barb at times; give dense cover and watch them at feeding.
- Your 200 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Clown Knifefish (90 cm) is big enough to swallow the 12 cm Mascara Barb whole.
- Clown Knifefish is aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Your 200 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Size gap is too large (100 vs 12 cm): Fire Eel will treat Mascara Barb as food.
- Expect Fire Eel to harass Mascara Barb at times; give dense cover and watch them at feeding.
- Your 200 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Koi (90 cm) is big enough to swallow the 12 cm Mascara Barb whole.
- Your 200 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Redtail Catfish (120 cm) is big enough to swallow the 12 cm Mascara Barb whole.
- Redtail Catfish is aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Your 200 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Size gap is too large (90 vs 12 cm): Spotted Gar will treat Mascara Barb as food.
- Spotted Gar clearly outsizes Mascara Barb and is aggressive; risky unless the tank is big and well-planted.
- Your 200 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Mascara Barb is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
- Expect Wels Catfish to harass Mascara Barb at times; give dense cover and watch them at feeding.
- Your 200 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Mascara Barb is bite-sized to a 72 cm predatory wolf cichlid — it will be eaten.
- Expect Wolf Cichlid to harass Mascara Barb at times; give dense cover and watch them at feeding.
- Your 200 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ 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.
Mascara Barb care specs
- Care level
- Medium
- Breeding
- Hard
- Max size
- 12 cm (4.7 in)
- Min tank size
- 200 L (52.8 gal)
- Temperature
- 20–25 °C (68–77 °F)
- pH
- 6–7.5
- Hardness
- 2–12 dGH
- Lifespan
- 5–8 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 8+ (shoaling)
- Family
- Cyprinidae
- Origin
- South-western India — fast-flowing rivers of the Western Ghats (Chalakudy and Periyar river systems)
What is a Mascara Barb?
The Mascara Barb (Dawkinsia assimilis) is a medium-to-large schooling cyprinid endemic to the swift hill streams of south-western India’s Western Ghats. Adults reach up to 12 cm (4.7 in) and are immediately recognisable by their silver-olive flanks, vivid red fins, and the bold black streak running through the eye — the “mascara” mark that names the species. Mature males develop elongated dorsal fin filaments that billow as the shoal moves, making a well-lit group one of the more striking sights in a mid-size freshwater display.
Despite being less commonly stocked than Tiger or Cherry Barbs, the Mascara Barb has a dedicated following among aquarists who want a larger, active schooling fish that stays peaceful with robust companions. Its medium care rating reflects the need for a sizable, well-oxygenated tank and a committed group — once those requirements are met it is a hardy, rewarding species.
Where does the Mascara Barb come from?
The species is native to the Chalakudy and Periyar river systems in Kerala, south-western India — part of the Western Ghats biodiversity hotspot. These rivers are characterised by fast-flowing, oxygen-saturated water over granite and rocky substrates, with moderate to heavy riparian tree cover providing dappled light and leaf litter. Water is soft to moderately hard (2–12 dGH), mildly acidic to neutral (pH 6.0–7.5), and cooler than many other Indian barbs due to the elevation of the source streams — temperatures in the range of 20–25 °C (68–77 °F).
Understanding this origin is the foundation of good husbandry. The Mascara Barb is adapted to clean, well-oxygenated, moving water, not the warm, still conditions of many South-East Asian tropical fish. Replicating those cool hill-stream conditions is what keeps this fish healthy long-term.
What tank size and setup does the Mascara Barb need?
A minimum tank volume of 200 litres (55 gal) is required, and larger is meaningfully better. This reflects both the fish’s eventual size of up to 12 cm (4.7 in) and the non-negotiable minimum group size of eight individuals — a shoal of eight adult Mascara Barbs occupies significant space and generates considerable activity throughout the water column.
Aquascape the tank to reflect the rocky, fast-water origin. A sandy or fine-gravel substrate with rounded river stones suits the species well. Robust plants that tolerate moderate flow — Vallisneria, Cryptocoryne, Java fern — work better than delicate stem plants buffeted by current. Leave an open central swimming area; Mascara Barbs are active, open-water swimmers that need room to shoal.
A canister filter rated generously for the tank volume, supplemented with a powerhead if needed, is the right filtration approach. Aim for moderate-to-strong current, good surface agitation, and scrupulous water quality — these fish are sensitive to organic waste buildup in a way that warmer-water tropical cyprinids often are not.
What water parameters does the Mascara Barb need?
- Temperature: 20–25 °C (68–77 °F). This cooler range is important and often overlooked. Sustained temperatures above 27 °C stress the species; a tank running at typical tropical 28 °C is unsuitable for long-term keeping.
- pH: 6.0–7.5. Soft, slightly acidic to neutral water mirrors the hill-stream origin.
- Hardness: 2–12 dGH. Moderately soft water is ideal; very hard, alkaline tap water should be buffered down.
Weekly water changes of 25–30% are recommended, particularly given the large tank and active group. Test regularly — declining nitrate management in a 200 L+ tank is the most common route to unexplained lethargy and colour loss.
What do Mascara Barbs eat?
Mascara Barbs are omnivores with little dietary fussiness in aquarium conditions. A quality omnivore flake or micro-pellet forms the staple, rotating in live or frozen foods — daphnia, brine shrimp, bloodworm, and mosquito larvae — two to three times per week. These protein supplements sharpen colour markedly, particularly the reds in the fins, and support conditioning in fish that are being prepared for breeding.
As active, fast-moving middle-column swimmers they will also graze on soft algae and accept vegetable-based wafers. Feed small portions two to three times daily rather than one large feeding; uneaten food in a well-stocked tank degrades water quality quickly. A varied diet is the simplest way to keep this species at its best.
How do Mascara Barbs behave — and what are good tank mates?
Mascara Barbs are classified as peaceful, and that label holds with suitable companions. They are not fin-nippers — a common concern with barbs — but they are fast, energetic, and assertive in the sense that they fill the tank with constant movement and compete confidently for food. Timid or slow-moving species placed with them often end up outcompeted and stressed, even without any direct aggression.
The ideal tank mates are medium-to-large, active, similarly robust fish that occupy different tank zones. Good pairings include Denison Barbs (Sahyadria denisonii — same river-system origin, same flow requirements), larger rainbowfish such as Melanotaenia species, rosy barbs, larger loaches including Botia species, and medium-to-large gouramis. Smaller nano fish, slow-moving fancy varieties, and long-finned forms that could be stressed by the pace should be avoided.
Within the shoal itself, males spar socially, particularly during feeding and displays. This is normal and harmless in a group of eight or more; the minimum group size exists precisely to spread that energy across multiple interactions rather than concentrating it on one or two subordinate fish.
For a full compatibility reference, see Mascara Barb tank mates.
How do you tell male and female Mascara Barbs apart?
Sexing is feasible in mature fish, though juveniles look similar for some months. Males develop elongated filaments on the dorsal fin — a distinctive streaming extension that becomes more pronounced as the fish matures — and display considerably more vivid red colouration in the fins and along the lateral line. Dominant males in good condition are noticeably brighter than females. Females are deeper-bodied, particularly when carrying eggs, and are plainer overall: shorter-finned, less intensely coloured, with a more rounded belly profile. In a mixed group of eight or more, the sex ratio typically becomes visible once the fish reach around 7–8 cm (2.75–3 in).
How do Mascara Barbs breed?
The Mascara Barb is rated hard to breed in captivity, and that rating is honest. In the wild the species undertakes seasonal migrations to spawn in fast-flowing shallows under specific temperature and rainfall cues that are difficult to replicate indoors.
Dedicated breeders use a separate breeding tank of around 100 L with strong filtration, fine-leaved spawning mops or Java moss for egg deposition, and a conditioning period of heavy live-food feeding. A slight temperature drop followed by a gradual raise can trigger spawning. The species is an egg scatterer that will eat its own eggs readily, so parents should be removed promptly after spawning. Fry are tiny and need infusoria or commercial fry food before progressing to micro-worm and baby brine shrimp. Expect low success rates on early attempts.
What diseases do Mascara Barbs commonly get?
Like most cyprinids, Mascara Barbs are susceptible to white spot (ich), especially after temperature fluctuations or the stress of transport. Ich presents as fine white grains across the body and fins and responds to early treatment and temperature management. Fin rot, caused by bacterial infection in poor water, can affect damaged fin edges — maintaining water quality prevents the overwhelming majority of cases. Velvet (Oodinium), a protozoal infection presenting as a gold dust sheen, is less common but worth knowing.
The cooler preferred temperature range (20–25 °C) reduces the risk of some bacterial pathogens that thrive at higher temperatures, but also means the species is intolerant of the temperature spikes that might be used therapeutically with warmer-water fish. Prevention — stable, clean, well-oxygenated water and a proper quarantine period for all new arrivals — is the correct strategy.
Health note: disease diagnosis and medication dosing are beyond the scope of a care profile. If your fish show persistent symptoms, cross-reference a veterinary or specialist fish-health source before treating. Misidentified disease and incorrect dosing cause more harm than the disease itself in many cases.
How long do Mascara Barbs live?
A well-maintained Mascara Barb lives between 5 and 8 years. Achieving the upper end of that range requires consistency above all: stable temperature in the correct 20–25 °C (68–77 °F) band, clean, oxygen-rich water, a shoal of eight or more to allow normal social behaviour, and a varied diet year-round. Fish kept in undersized groups, in tanks with inadequate flow, or at sustained temperatures above their comfort range rarely reach their potential lifespan. Get the fundamentals right and this is a species that rewards the investment with years of active, colourful display.
Frequently asked questions
Is the Mascara Barb fin-nip prone?
No — unlike Tiger Barbs, Mascara Barbs are not known fin-nippers. They are boisterous and fast, however, which can stress timid or slow-moving tank-mates, so pair them with similarly active, robust species.
How many Mascara Barbs should I keep together?
A minimum of eight is strongly recommended. In smaller groups males compete aggressively with each other; in a large, well-balanced shoal that energy is diffused and all fish are more relaxed and display better colour.
What you need to keep a mascara barb
The baseline is a heated, filtered 200 L+ tank: a reliable heater to hold 20–25 °C (68–77 °F), a gentle filter that won't batter a mascara barb in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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