Bristlenose catfish - Ancistrus sp.

Scientific name: Ancistrus sp.

Common name: Bristlenose catfish

Family: Loricariidae

Usual size in fish tanks: 10 - 12 cm (3.94 - 4.72 inch)

014

Recommended pH range: 5.8 - 7.8

Recommended water hardness: 4 - 18°N (71.43 - 321.43ppm)

0°C 32°F30°C 86°F

Recommended temperature range: 22 - 26 °C (71.6 - 78.8°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Bottom levels

Short description

The Bristlenose catfish (Ancistrus sp.) is a small, hardy loricariid widely kept for its constant grazing and easygoing temperament. Most “bristlenose” in the trade descend from domestic forms of Ancistrus cf. cirrhosus and related species; husbandry is similar across these strains. Males develop the characteristic facial bristles (tentacles). Peaceful with other fish, but adult males can be territorial toward rival males—especially around caves.

Origin

South America — various Amazon/Orinoco drainages and foothill streams with wood, leaf litter, and moderate flow. Aquarium forms are largely domesticated, but still prefer clean, well-oxygenated water and stable parameters.

Food and feeding

An aufwuchs/biofilm grazer with omnivorous habits. Provide sinking algae/spirulina wafers and quality pleco pellets as staples; supplement with blanched vegetables (zucchini, cucumber, spinach, green beans) and small amounts of protein (bloodworms, daphnia, finely chopped shrimp) 1–3× weekly. Offer a piece of driftwood for grazing and dietary fiber. Do not rely solely on “algae cleanup”; balanced feeding is essential once surfaces are clean.

Sexing

Males develop prominent bristles on the snout and may have stronger cheek/flank odontodes; females are typically smaller, rounder when gravid, with little or no bristling (often limited to the snout edge).

Breeding

A classic cave spawner. Provide tight caves/tubes with a single entrance. The female lays a clutch inside; the male guards and fans the eggs. At 25–27 °C, eggs usually hatch in ~4–6 days; fry absorb yolk for another 3–5 days. Start them on powdered algae foods, crushed wafers, blanched greens, and later baby brine shrimp/cyclops. Keep oxygen high and water very clean.

Lifespan

Commonly 8–12 years with good care (15 years is possible but exceptional).

Behavior & compatibility

Generally peaceful community fish. Keep singly or with multiple individuals only if the tank has several caves and broken sightlines to limit male–male disputes. Compatible with tetras/rasboras, peaceful cichlids, Corydoras, and other non-aggressive tank mates of similar size.

Tank requirements

Tank size: ~80–120 L for a single adult; more volume for multiple fish or breeding.
Aquascape: sand or smooth gravel, driftwood, smooth stones/slate for biofilm, and multiple snug caves.
Water: pH 5.8–7.8, soft to moderately hard; temperature 22–26 °C. Prioritize stability and low nitrate.
Filtration: robust biofiltration; weekly partial water changes to keep organics down.
Lighting: moderate or subdued; allow controlled biofilm on hardscape for natural grazing.