Photo: The Last 99 (CC BY-SA 3.0 de) — via Wikimedia Commons
Bristlenose Pleco (Ancistrus cirrhosus)
The community tank's hardest-working algae crew — a small, peaceful, armoured catfish that actually stays a sensible size.
Will it live with a Bristlenose Pleco?
We compare each fish against your bristlenose pleco on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Agassiz's Dwarf Cichlid✅ CompatibleSemi-aggressive · 9 cm · Medium care · 24–30 °C (75–86 °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 bottom of the tank — offer enough cover so they aren't always in each other's space.
- Banded Gourami✅ CompatibleSemi-aggressive · 12 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Banjo Catfish✅ CompatiblePeaceful · 15 cm · Medium care · 20–26 °C (68–79 °F)
- Both are peaceful, and their water overlaps around 23–26 °C — no size, zone or temperament conflicts.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Bearded Corydoras✅ CompatiblePeaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
- Compatible on the things that matter: shared water near 23–24 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Keep Bearded Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Brilliant Rasbora✅ CompatiblePeaceful · 9 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Brilliant Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Burmese Loach✅ CompatiblePeaceful · 9 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 bottom of the tank — offer enough cover so they aren't always in each other's space.
- Giant Betta✅ CompatiblePeaceful · 12 cm · Medium 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.
- Giant Kuhli Loach✅ CompatiblePeaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
- Compatible on the things that matter: shared water near 24–30 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Golden Wonder Killifish✅ CompatibleSemi-aggressive · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keyhole Cichlid✅ 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.
- Kribensis✅ CompatibleSemi-aggressive · 10 cm · Easy care · 24–27 °C (75–81 °F)
- Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Kuhli Loach✅ CompatiblePeaceful · 10 cm · Easy care · 24–30 °C (75–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Marbled Hoplo✅ CompatiblePeaceful · 14 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 bottom of the tank — offer enough cover so they aren't always in each other's space.
- 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.
- Murray River Rainbowfish✅ CompatiblePeaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
- Both are peaceful, and their water overlaps around 23–26 °C — no size, zone or temperament conflicts.
- 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 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Porthole Catfish✅ CompatiblePeaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Rosy Barb✅ CompatibleSemi-aggressive · 10 cm · Easy care · 18–26 °C (64–79 °F)
- Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rosy Barb in a shoal of 6+ or it gets stressed and nippy.
- Spotted Rubbernose Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Both are peaceful, and their water overlaps around 23–26 °C — no size, zone or temperament conflicts.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Striped Eel Loach✅ CompatiblePeaceful · 12 cm · Medium 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 bottom of the tank — offer enough cover so they aren't always in each other's space.
- Swordtail✅ CompatibleSemi-aggressive · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- 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 23–27 °C — no size, zone or temperament conflicts.
- Topaz Cichlid✅ CompatibleSemi-aggressive · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Zebra Pleco✅ CompatiblePeaceful · 10 cm · Hard care · 26–30 °C (79–86 °F)
- Compatible on the things that matter: shared water near 26–30 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the bottom of the tank — offer enough cover so they aren't always in each other's space.
- Arrowhead Puffer⚠️ With cautionAggressive · 12 cm · Hard care · 23–28 °C (73–82 °F)
- Your 95 L tank is below the ~132 L this pairing really wants — crowding raises aggression.
- 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.
- Your 95 L tank is below the ~190 L this pairing really wants — crowding raises aggression.
- Keep Auratus Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Blue Gourami⚠️ With cautionSemi-aggressive · 13 cm · Easy care · 22–28 °C (72–82 °F)
- Your 95 L tank is below the ~113 L this pairing really wants — crowding raises aggression.
- Bucktooth Tetra⚠️ With cautionAggressive · 12 cm · Medium care · 23–28 °C (73–82 °F)
- Your 95 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep Bucktooth Tetra 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)
- Your 95 L tank is below the ~110 L this pairing really wants — crowding raises aggression.
- Ice Blue Cichlid⚠️ With cautionAggressive · 12 cm · Medium care · 24–28 °C (75–82 °F)
- pH preferences only just meet (Bristlenose Pleco 6–7.5 vs Ice Blue Cichlid 7.6–8.6) — target the overlap and acclimate slowly.
- Your 95 L tank is below the ~190 L this pairing really wants — crowding raises aggression.
- Mascara Barb⚠️ With cautionPeaceful · 12 cm · Medium care · 20–25 °C (68–77 °F)
- Your 95 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Medusa Pleco⚠️ With cautionPeaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
- Your 95 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Pearl Gourami⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Your 95 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Pictus Catfish⚠️ With cautionSemi-aggressive · 12 cm · Medium care · 22–27 °C (72–81 °F)
- Your 95 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
- Polka-dot Loach⚠️ With cautionSemi-aggressive · 13 cm · Medium care · 24–28 °C (75–82 °F)
- Your 95 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
- Powder Blue Cichlid⚠️ With cautionSemi-aggressive · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Your 95 L tank is below the ~170 L this pairing really wants — crowding raises aggression.
- Keep Powder Blue Cichlid in a shoal of 6+ 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 (Bristlenose Pleco 6–7.5 vs Red Zebra Cichlid 7.6–8.6) — target the overlap and acclimate slowly.
- Your 95 L tank is below the ~190 L this pairing really wants — crowding raises aggression.
- Keep Red Zebra Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Rubber Lip Pleco⚠️ With cautionPeaceful · 12 cm · Easy care · 20–26 °C (68–79 °F)
- Your 95 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- T-bar Cichlid⚠️ With cautionSemi-aggressive · 12 cm · Medium care · 22–28 °C (72–82 °F)
- Your 95 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
- 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.
- Your 95 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep White Spotted Cichlid in a shoal of 8+ or it gets stressed and nippy.
- Goldfish⛔ Not recommendedPeaceful · 30 cm · Medium care · 18–22 °C (64–72 °F)
- Temperature needs don't overlap (Bristlenose Pleco 23–30 °C vs Goldfish 18–22 °C).
- Goldfish may bully the smaller Bristlenose Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Your 95 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Imperial Flower Loach⛔ Not recommendedSemi-aggressive · 50 cm · Hard care · 15–22 °C (59–72 °F)
- Temperature needs don't overlap (Bristlenose Pleco 23–30 °C vs Imperial Flower Loach 15–22 °C).
- Imperial Flower Loach may bully the smaller Bristlenose Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Your 95 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
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.
Bristlenose Pleco care specs
- Care level
- Easy
- Breeding
- Medium
- Max size
- 12 cm (4.7 in)
- Min tank size
- 95 L (25.1 gal)
- Temperature
- 23–30 °C (73–86 °F)
- pH
- 6–7.5
- Hardness
- 2–15 dGH
- Lifespan
- 5–12 years
- Diet
- Herbivore
- Swim level
- Bottom
- Group size
- Best alone or in a pair
- Family
- Loricariidae
- Origin
- Rivers of South America (Amazon basin)
What is a bristlenose pleco?
The bristlenose pleco (Ancistrus cirrhosus), also sold as the bushynose pleco or BN pleco, is a small armoured catfish from the family Loricariidae — the suckermouth catfishes. Its common name comes from the bushy, fleshy tentacles that adult males grow across their snouts, giving them a distinctive, almost prehistoric look that surprises many first-time buyers.
What makes the bristlenose genuinely special is its size. While the common pleco is one of the most widely sold — and most widely regretted — fish in the hobby, growing past 45 cm (18 in) and consuming entire tanks’ worth of oxygen, the bristlenose stays compact at around 12 cm (5 in). It is easy to care for, thoroughly peaceful, and one of the most effective algae-grazers available for a community tank. Colour varieties including albino, calico, and long-fin forms are widely available; all share the same care requirements.
Where do bristlenose plecos come from?
Bristlenose plecos originate from the river systems of South America, centred on the Amazon basin. In the wild they inhabit fast-flowing, well-oxygenated rivers and streams with sandy or rocky substrates, submerged wood, and plenty of leaf litter. Water in these environments is typically soft, slightly acidic, and warm — conditions the aquarium hobby broadly replicates with their recommended parameters.
The species is now one of the most commonly bred plecos in captivity. Most fish available in stores are tank-bred rather than wild-caught, which means they tend to be robust and well-adapted to a modest range of water conditions.
What size tank does a bristlenose pleco need?
The recommended minimum is 95 litres (25 gallons). This gives a single bristlenose adequate swimming room at the bottom, space for the driftwood, caves, and flat surfaces it needs, and enough water volume to dilute waste — these fish are notable producers.
Because they are strictly bottom-dwelling, the footprint of the tank matters more than height. A longer, shallower tank gives more usable territory than a tall, narrow column. If you plan to keep a pair or add tank-mates that also occupy the bottom level, step up to 150 L (40 gal) or more to prevent territorial friction.
Good water flow is appreciated but not mandatory. The filter should turn the tank volume over several times per hour, since clean water is far more important for their health than any specific current speed.
What water parameters do bristlenose plecos need?
- Temperature: 23–27 °C (73–81 °F). They tolerate a slightly broader band than many tropicals but do best in the middle of this range.
- pH: 6.0–7.5. Slightly acidic to neutral is ideal; hard alkaline water should be avoided.
- Hardness: 2–15 dGH — a wide tolerance, though softer water reflects their Amazonian origin.
Consistent, clean water matters most. Bristlenose plecos are sensitive to ammonia and nitrite spikes and, because they are bottom-dwellers, they are among the first to show signs of poor water quality. Perform weekly water changes of 25–30%, vacuum the substrate, and test regularly. Avoid using medications with heavy metals or copper — these are toxic to all loricariids.
What do bristlenose plecos eat?
Bristlenose plecos are herbivores. Their primary role in the tank is grazing algae from glass, hardscape, and plant leaves, and they are effective at it — but algae alone will not sustain them long-term.
A balanced diet should include:
- Sinking algae wafers as the core staple, offered in the evening when the fish are most active.
- Blanched vegetables: zucchini (courgette), cucumber, spinach, and sweet potato are all accepted. Blanching softens cell walls so the fish can rasp them efficiently.
- Driftwood — not just decoration. Bristlenose plecos actively rasp wood as part of normal digestion. A piece of bogwood or spider wood in the tank is a dietary requirement, not optional.
Remove uneaten vegetables after 24 hours to prevent fouling the water. Protein-based foods are not necessary and may upset their digestive system if offered regularly.
Are bristlenose plecos aggressive — and what fish can live with them?
Bristlenose plecos are peaceful toward almost everything in the tank. They are armoured and confident but not combative, and they typically ignore fish swimming at higher levels. The one caveat is conspecific aggression between males: two males in a confined space, particularly around a cave, will compete and may injure each other. In most community tanks a single bristlenose — or one male with one or more females — is the safest arrangement.
They make excellent tank-mates for peaceful community fish across virtually all size ranges: tetras, rasboras, livebearers, dwarf cichlids, corydoras, and even bettas all coexist without problems. Avoid housing them with aggressive cichlids that may harass a slow-moving, bottom-dwelling fish, or with species known to pick at flat, soft-bodied fish.
For a full, filterable list of compatible species, see Bristlenose Pleco tank mates.
How do you tell male and female bristlenose plecos apart?
Sexing bristlenose plecos is one of the easier tasks in the hobby once the fish are mature. Males develop the characteristic fleshy, branching tentacles — the “bristles” — across their snouts and around the edge of the head. These grow progressively longer and more elaborate with age. Females may develop a few small bristles around the mouth edge, but nothing approaching the dramatic display of a mature male.
Body shape offers a secondary clue: females tend to be slightly broader across the abdomen, particularly when carrying eggs. In juveniles under around 5–6 cm (2 in), sexing can be difficult; wait until the tentacles become obvious on males before drawing conclusions.
How do bristlenose plecos breed?
Bristlenose plecos are cave-spawners and one of the more beginner-accessible species to breed in captivity, which is why captive-bred stock is so widely available.
The male selects and defends a cave — a terracotta tube, a hollow piece of driftwood, or a commercial pleco cave all work. Once a female is ready to spawn, she enters the cave; the male fertilises the clutch of orange eggs and then takes over sole parental duty, fanning the eggs with his fins and guarding the entrance. The eggs hatch in five to ten days depending on temperature, and the male continues to tend the fry until they are free-swimming and self-sufficient.
To encourage breeding, condition the pair with a varied diet including vegetables and quality foods, maintain clean water, and ensure a suitable cave is available. A slight drop in water temperature followed by a large water change can simulate the onset of the rainy season and trigger spawning. We rate breeding difficulty as medium — the fish do most of the work, but raising a clutch of fry to saleable size requires preparation.
What are common bristlenose pleco diseases?
Bristlenose plecos are hardy, but a few conditions appear regularly:
- Ich (white spot): Small white cysts on the body and fins. Often triggered by temperature drops or stress from new arrivals. Raise temperature gradually and maintain clean conditions at first sign.
- Hole-in-the-head disease (HLLE): Pitting erosions on the head, associated with poor water quality and nutritional deficiencies. The most effective prevention is pristine water and a varied, vegetable-rich diet.
- Digestive issues from an incorrect diet: A bristlenose fed primarily protein-based foods or kept without driftwood may develop bloating or pass abnormal waste. Diet correction is the fix.
- Bacterial infections and fin damage: Can result from fighting (usually between males) or sharp décor. Round off any rough hardscape edges and separate males if conflict is observed.
Prevention in all cases follows the same logic: stable, clean water, a correct diet, and appropriate tankmates.
Health note: disease diagnosis and medication selection are beyond the scope of a care profile. Confirm symptoms against a reputable veterinary or fish-health source before medicating, and be aware that copper-based treatments are toxic to bristlenose plecos and other loricariids.
How long do bristlenose plecos live?
With good care, a bristlenose pleco lives 5–12 years, and accounts of fish reaching the upper end of that range are not unusual. They are long-term commitments for a fish that is often bought on impulse as “the algae cleaner.” Provide consistent water quality, a complete and varied diet, and a tank with suitable décor, and a bristlenose will be a low-maintenance, productive — and genuinely characterful — resident for a decade or more.
Frequently asked questions
Is a bristlenose pleco better than a common pleco?
For most tanks, yes. A common pleco reaches 45 cm+ and outgrows nearly every home aquarium; a bristlenose tops out around 12 cm, so it does the same algae-grazing job without becoming a monster.
Do bristlenose plecos need driftwood?
Yes — they rasp on wood as part of their diet and digestion. Provide driftwood plus algae wafers and blanched vegetables; algae alone isn't enough.
What you need to keep a bristlenose pleco
The baseline is a heated, filtered 95 L+ tank: a reliable heater to hold 23–30 °C (73–86 °F), a gentle filter that won't batter a bristlenose pleco in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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