Corydoras

Also known as: Corydoras aeneus

Corydoras aeneus, commonly known as the bronze corydoras, is a small, armored catfish native to slow-moving, sandy-bottomed streams and tributaries of the Amazon Basin. The Corydoras originates from South America, specifically the Amazon River basin in Brazil, Colombia, Venezuela, and Peru, reaches Adult size: 6-7 cm in captivity, typically lives 5-8 years, and is kept at 22-26°C (72-79°F). Individual fish vary, so treat this as a general guide rather than a guarantee.

Key facts

Lifespan: 5-8 years.
Adult size: Adult size: 6-7 cm (2.4-2.8 inches).
Temperament: Peaceful, social, and bottom-dwelling; thrives in groups of 6 or more.
Minimum tank: Minimum 60 liters (16 gallons) for a group of 6; 80+ liters (21+ gallons) recommended for larger schools.
Water temperature: 22-26°C (72-79°F).
pH range: 6.0-7.8.

Species at a glance

Origin: South America, specifically the Amazon River basin in Brazil, Colombia, Venezuela, and Peru
Adult size: Adult size: 6-7 cm (2.4-2.8 inches)
Life span: 5-8 years
Temperament: Peaceful, social, and bottom-dwelling; thrives in groups of 6 or more
Tank size: Minimum 60 liters (16 gallons) for a group of 6; 80+ liters (21+ gallons) recommended for larger schools
Water temp: 22-26°C (72-79°F)
pH range: 6.0-7.8
Diet: Omnivorous; accepts sinking pellets, wafers, frozen bloodworms, brine shrimp, and blanched vegetables; requires varied diet to maintain health
Other names: Corydoras aeneus

About the Corydoras

Corydoras aeneus, commonly known as the bronze corydoras, is a small, armored catfish native to slow-moving, sandy-bottomed streams and tributaries of the Amazon Basin. It features a distinctive bronze or greenish iridescent body with dark markings along the lateral line and barbels adapted for foraging in substrate. This species is highly social and exhibits natural schooling behavior, constantly sifting through gravel or sand in search of food. Its peaceful nature and hardy disposition make it one of the most popular bottom-dwellers in community aquariums.

Lifespan and health

With optimal care, Corydoras aeneus typically lives 5-8 years in captivity, though exceptional specimens may reach 10 years under pristine conditions. Lifespan is strongly influenced by water quality, diet consistency, and social grouping; fish kept in isolation or poor conditions often succumb to stress-related illnesses within 2-3 years. Regular monitoring of water parameters and prompt correction of imbalances are critical to maximizing longevity. Common health issues include barbel erosion from abrasive substrates or poor water quality, which can lead to infection if untreated; prevent by using sand substrate and maintaining ammonia/nitrite at 0 ppm. Ich (white spot disease) is frequent in newly introduced or stressed fish; treat with gradual temperature increase to 28°C (82°F) for 10 days and appropriate medication. Fungal infections (e.g., cotton wool disease) may occur on damaged skin or fins; improve water quality and use antifungal treatments like methylene blue or Pimafix. Internal parasites (e.g., nematodes) can cause wasting; quarantine new fish and feed varied, high-quality diet to bolster immunity. Avoid copper-based medications, as Corydoras are highly sensitive to them.

Overview

Care and tank setup

Tank setup should include a soft, fine sand substrate (minimum 2-3 cm depth) to protect their delicate barbels from abrasion; avoid sharp gravel or coarse materials. Provide hiding spots with driftwood, smooth rocks, and dense planting (e.g., Java fern, Anubias) to mimic natural habitat and reduce stress. Maintain gentle water flow with a sponge filter or low-output canister filter to prevent strong currents that can exhaust these bottom-dwellers. Water parameters must be stable: perform 25% weekly water changes using dechlorinated water matched to tank temperature; monitor ammonia and nitrite at 0 ppm, nitrate below 20 ppm. Use a reliable heater to maintain 22-26°C (72-79°F) and test pH weekly to ensure it remains within 6.0-7.8. Avoid sudden fluctuations in temperature or chemistry, as Corydoras are sensitive to poor water quality despite their hardiness. Feed a varied diet 2-3 times daily in small amounts they can consume within 2-3 minutes; prioritize sinking foods like Corydoras-specific pellets or algae wafers supplemented 2-3 times weekly with frozen or live foods such as bloodworms, daphnia, or brine shrimp. Include blanched zucchini or spinach once weekly for plant matter. Overfeeding must be avoided to prevent water quality degradation and obesity. Tankmates should be peaceful, mid-to-top dwelling species that share similar water requirements; ideal companions include small tetras (e.g., neon, ember), rasboras, dwarf gouramis, and peaceful dwarf cichlids like Apistogramma. Avoid aggressive or nipping fish (e.g., tiger barbs, large cichlids) and bottom-dwellers that compete for food or space (e.g., loaches, larger catfish). Keep Corydoras in groups of at least 6, preferably 8-10, to encourage natural schooling behavior and reduce stress.

Adding a Corydoras? Research the species’ adult size and temperament carefully, quarantine new fish before introducing them to your tank, and buy from reputable aquarium stores or breeders.

Sources

Breed information on this page is based on the Wikipedia article on the Corydoras, supplemented with additional research. Reviewed for accuracy.