Ancistrus cf. cirrhosus
The 'bushy nose' pleco, males develop branched tentacle-like bristles on their head. Practical algae crew that actually eats algae (unlike common plecos). Stays small enough for a 100 L planted tank. Requires driftwood for digestion and cave for territorial security.
Bristlenose Pleco (Ancistrus cf. cirrhosus) reaches 10–15 cm as an adult and needs a minimum tank of 100 L. Native to Amazon and Orinoco basins, South America, it lives in the bottom water column with a peaceful temperament. Aim for 20–28 °C, pH 6.0–7.5, and 2–20 dGH hardness. Lifespan is 10–15 years with good care. Bristlenose Pleco can be kept singly or in a small group. Diet: omnivore (algae-leaning), Algae wafers, blanched zucchini, courgette, soft green algae, occasional protein (frozen bloodworms). Driftwood is essential, they rasp it for cellulose. Plant-safe: Yes. Shrimp-safe: Yes.
Care at a glance
The 'bushy nose' pleco, males develop branched tentacle-like bristles on their head. Practical algae crew that actually eats algae (unlike common plecos). Stays small enough for a 100 L planted tank. Requires driftwood for digestion and cave for territorial security.
By Mike ElmiraUpdated 2 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether bristlenose pleco fits in your tank.
Bottom
No
Solo or a pair
Loricariidae
Omnivore (algae-leaning)
Algae wafers, blanched zucchini, courgette, soft green algae, occasional protein (frozen bloodworms). Driftwood is essential, they rasp it for cellulose.
10–15 yrs
Easy
Fast oxygenated rivers of the Amazon basin
Amazon and Orinoco basins, South America
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Most peaceful community fish. Cherry barbs, white clouds, tetras, gouramis, otocinclus (different niche, no competition), corydoras.
Other large bottom-dwellers (territorial conflicts), aggressive cichlids that bully them, anything that competes for caves.
Hard-won lessons from the tank.
Run a single male per tank to avoid territorial conflict. Provide one cave per male — they pick the deepest darkest spot and defend it. They produce significant waste; a slightly oversized filter compared to bioload is essential. Will eat plants only if starved; well-fed bristlenose ignore plants entirely.
Genus 'Ancistrus' = 'fishhook' (referring to the cheek bristles). Common name 'bristlenose' is descriptive.
What can go wrong and how to spot it.
Failure modes, in order of how dramatic the fix is.
Robust. Watch for ich during temperature drops. Susceptible to swim-bladder issues if fed too much protein.
Often confused with the much larger common pleco (Hypostomus plecostomus) which grows to 45+ cm and outgrows almost all home tanks. Bristlenose stays manageable at 10–15 cm. Always verify species when buying 'pleco'.
The practical routine, read top to bottom.
100 L+ with sandy or fine gravel substrate. Driftwood is non-negotiable — they require it for digestion. Caves (PVC pipe, terracotta pot, coconut shell). Moderate flow with good oxygenation. Temperature 20–28 °C — they're surprisingly cool-tolerant.
3 weeks. Include driftwood in QT — they can stop eating in bare tanks.
Where it comes from, how it behaves, and the variants you'll see at retail.
Where it lived before it came home.
Fast-flowing rivers and streams across the Amazon and Orinoco basins. Sandy and rocky substrates, abundant driftwood, leaf litter. Often found wedged into rock crevices during daylight.
Soft green algae, biofilm, aufwuchs, decomposing wood (cellulose). Occasional protein from drift insects.
Multiple Ancistrus species are wild-caught from Amazonian fisheries. The common bristlenose in trade is captive-bred globally and represents no conservation concern.
How they pair, reproduce, and grow.
Mature males develop branched tentacle-like bristles on the head and snout; females have shorter and fewer bristles, often only along the snout edge. Adults are easy; juveniles are nearly impossible to sex.
Easy in captivity. Cave spawners — male claims a cave or PVC pipe, attracts a female, fertilises eggs, then guards the cave fanning eggs continuously for 4–10 days. Fry are tiny replicas of adults, attaching to glass and wood immediately and feeding on biofilm.
The named cultivars and the lookalikes worth flagging.
Common wild type (mottled brown), 'Albino' (yellow body, red eyes), 'Long-fin' (extended dorsal and caudal), 'Calico' (multi-coloured marbling), 'Super Red' (bright orange-red). Ancistrus has 70+ described species; commercial 'bristlenose' usually refers to A. cf. cirrhosus.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Bristlenose Pleco (Ancistrus cf. cirrhosus) needs a minimum tank of 100 L. They live in the bottom water column and can be kept singly, so a longer footprint matters more than depth.
Target 20–28 °C, pH 6.0–7.5, and 2–20 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Yes. Plant safety: Yes.
Bristlenose Pleco are omnivore (algae-leaning). Algae wafers, blanched zucchini, courgette, soft green algae, occasional protein (frozen bloodworms). Driftwood is essential, they rasp it for cellulose.
On Fin & Stem's 1–5 difficulty scale this species rates 2/5. Forgiving, beginner-friendly once the tank is cycled. Breeding difficulty: easy.
Typical lifespan in a well-maintained tank is 10–15 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
