Common Bristlenose Catfish (Ancistrus sp.)

The Common Bristlenose Catfish is the perfect beginner's pleco, a tireless algae fighter and reliable tank cleaner.

Overview

The Common Bristlenose Catfish (Ancistrus sp.), also known as the Bristlenose Pleco or Bushy Nose Catfish, is one of the most popular and widespread aquarium fish in the world. A member of the armored catfish family (Loricariidae), it originates from rivers and tributaries of South America — the Amazon, Orinoco, and Parana basins. Thanks to its hardiness, useful qualities, and interesting behavior, the bristlenose has become an integral part of most community aquariums.

The body of Ancistrus sp. is flattened and covered with rows of bony plates providing protection from predators. Coloration varies from dark brown to black with a scattering of light spots or dots. The mouth is transformed into a powerful sucker, allowing the fish to cling to various surfaces and effectively scrape algae growth.

Adults reach a size of 8-10 cm, with females typically slightly smaller than males. Lifespan with proper care is 8-12 years. The main distinguishing feature of males is characteristic fleshy growths (tentacles) on the head, which develop as they mature and are especially prominent in sexually mature individuals. In females, these growths are absent or minimally expressed.

The bristlenose is primarily nocturnal. During the day it hides in shelters, emerging at dusk to search for food, methodically working over aquarium surfaces with its mouth. This makes it an invaluable helper in the fight against algae.

Popular Varieties

Many species and selectively bred forms of bristlenose catfish are found in the aquarium hobby:

• Starlight Bristlenose (Ancistrus cirrhosus) — distinguished by bright starry coloration with contrasting white spots on a dark background.
• Longfin Bristlenose (Ancistrus dolichopterus) — features magnificent elongated fins.
• Albino Bristlenose — a selectively bred form with pale yellow or white body and red eyes.
• Super Red Bristlenose — a bright red-orange selectively bred form.

Tank Requirements

The Common Bristlenose Catfish is one of the most undemanding aquarium fish, but certain basic requirements should be met for comfortable keeping.

• Tank Volume: The minimum volume for a single specimen is 80 liters. For a pair or keeping with other fish, an aquarium of 100-120 liters is recommended. In a spacious tank, the bristlenose feels more confident and displays more interesting behavior.

• Water Temperature: The optimal range is 24-28°C. Bristlenose catfish can tolerate short-term temperature fluctuations, but stable conditions are preferable.

• Water Parameters:

  • pH: 6.5-7.5 (slightly acidic to neutral)
  • General Hardness (GH): 6-12 dGH
  • Ammonia, Nitrites: 0 ppm
  • Nitrates: <30 ppm Bristlenose catfish are quite hardy, but clean water is the key to their health.

• Lighting: They prefer subdued lighting. Under bright light, they will spend most of their time hiding. Create shaded areas using floating plants or dense vegetation.

• Tank Setup:

  • Substrate: Any type — sand, gravel, or pebbles. Avoid sharp-edged substrates.
  • Hiding Spots: An essential element! Driftwood, ceramic tubes, caves, coconut halves. Each bristlenose needs its own hiding spot.
  • Driftwood: Critically important — serves not only as shelter but also as a source of cellulose for digestion. Natural driftwood (mopani, mangrove) should be present in the aquarium.
  • Plants: Live plants are welcome. Bristlenose catfish typically don't damage hard-leaved species (Anubias, ferns, Cryptocorynes).

• Flow and Aeration: Moderate current and good aeration. Bristlenose catfish originate from oxygen-rich river waters.

Feeding and Diet

The Common Bristlenose is primarily herbivorous, but in nature also feeds on detritus and small organisms. A varied diet is key to health and longevity.

• Main Diet:

  • Algae: The natural food of bristlenose catfish. They actively scrape algae growth from glass, decorations, and plants. Don't completely eliminate algae from the tank — a small amount is actually beneficial.
  • Specialized Foods: Sinking tablets and wafers for catfish based on spirulina. Choose quality foods from reputable manufacturers.
  • Vegetables: Regularly offer fresh vegetables — a favorite treat for bristlenose catfish:
    • Zucchini, cucumbers: Slice into rounds, blanch, and secure at the bottom.
    • Spinach, lettuce: Blanch and weigh down with a rock.
    • Pumpkin, carrots, broccoli: Boil until soft.
  • Driftwood: Bristlenose catfish constantly scrape soft fibers from driftwood, obtaining necessary cellulose.

• Supplemental Feeding:

  • Protein Supplements: 1-2 times weekly, offer frozen bloodworms, brine shrimp, or daphnia. Protein is important for growth and health, but excess is harmful.
  • Dry Foods: Quality flakes or pellets for omnivorous fish can serve as a supplement.

• Feeding Schedule: Feed once daily, preferably in the evening. Bristlenose catfish are most active at night and will find food after lights go out. Remove uneaten vegetables after 12-24 hours.

Important: A common misconception is that bristlenose catfish can survive solely on algae in the aquarium. This is not true! Proper nutrition requires regular feeding with specialized foods and vegetables.

Care and Maintenance

Caring for bristlenose catfish is simple, making them ideal fish for beginning aquarists.

• Regular Water Changes: Weekly water changes of 25-30% of tank volume. This maintains water quality and removes accumulated pollutants.

• Filtration: Use a reliable filter with good mechanical and biological filtration. Bristlenose catfish produce significant waste, so effective filtration is important.

• Aeration: Ensure good water oxygenation, especially at higher temperatures.

• Substrate Cleaning: Regularly siphon the substrate, removing food remnants and waste. Pay special attention to areas under hiding spots.

• Health Monitoring: A healthy bristlenose has a rounded belly (not sunken), vibrant coloration, and is active at night. A sunken belly may indicate insufficient nutrition or disease.

• Quarantine New Fish: Always quarantine new bristlenose catfish before adding them to the main tank.

Compatibility

The Common Bristlenose Catfish is one of the most peaceful aquarium fish, ideal for community tanks.

• Ideal Tankmates:

  • Characins: Neons, tetras, serpae tetras, rummy-nose tetras.
  • Cyprinids: Danios, rasboras, barbs (except large aggressive species).
  • Livebearers: Guppies, swordtails, platies, mollies.
  • Cichlids: Peaceful species — angelfish, Apistogrammas, Pelvicachromis.
  • Other Catfish: Corydoras, otocinclus, whiptail catfish.
  • Labyrinth Fish: Gouramis, dwarf gouramis, bettas (in spacious tanks).
  • Shrimp and Snails: Compatible with larger shrimp (Amano, filter shrimp) and snails.

• Unsuitable Tankmates:

  • Large Aggressive Cichlids: Oscars, cichlasomas, acaras.
  • Predatory Fish: Those that may view the bristlenose as prey.

• Intraspecies Compatibility:

  • Males may show territoriality toward each other.
  • When keeping multiple males, provide sufficient hiding spots — at least one per fish.
  • Optimal ratio: one male to 2-3 females.

Breeding

Breeding bristlenose catfish is one of the simplest processes among aquarium catfish, accessible even to beginning aquarists.

• Sex Determination:

  • Males are larger with developed bushy tentacles on the head.
  • Females are smaller; tentacles are absent or weakly expressed (small bumps along the snout edge).

• Spawning Preparation:

  • Breeding Tank: Can use the main aquarium or a separate tank of at least 50 liters.
  • Hiding Spots: Spawning tubes or caves are essential. The shelter size should allow the male to turn around inside.
  • Stimulation: Frequent water changes (2-3 times weekly at 20-30%) with cooler water simulate the rainy season.
  • Conditioning: Increased feeding of breeders with protein-rich foods for 1-2 weeks before spawning.

• Spawning Process:

  • The male selects a shelter and thoroughly cleans it.
  • The ready female enters the shelter and deposits 30-100 large orange eggs.
  • After laying, the female is chased away, and the male takes over all care for the offspring.
  • The male guards the clutch, fans the eggs with his fins, and removes dead eggs.

• Offspring Development:

  • Incubation lasts 4-6 days at 26-28°C.
  • Hatched larvae feed on their yolk sac for 3-5 days.
  • After becoming free-swimming, fry begin feeding independently.
  • First Foods: Finely crushed spirulina tablets, specialized fry foods, blanched vegetables.
  • Fry grow quickly — reaching 2-3 cm by 3 months.

The Common Bristlenose Catfish is a versatile aquarium inhabitant combining usefulness, interesting behavior, and ease of care. It's the ideal choice for a first catfish and an indispensable helper in maintaining aquarium cleanliness.