Description
Cardinal Tetra (Paracheirodon axelrodi)
Overview
Paracheirodon axelrodi, commonly known as the Cardinal Tetra, is a small, vibrant freshwater fish native to the upper Orinoco and Negro River basins in South America, primarily in Brazil, Colombia, and Venezuela. Renowned for its dazzling neon blue stripe above a vivid red band that spans the entire body, it is one of the most iconic aquarium fish. Cardinal Tetras are peaceful, schooling fish that thrive in well-maintained, stable environments, making them a favorite for aquarists despite their sensitivity to water conditions.
Care Requirements
Tank Size:
Minimum 60 litres for a school of 6–12 fish; 100 litres or larger is ideal to accommodate their schooling behaviour and provide ample swimming space.
Water Parameters:
- Temperature: 23–27°C; 26°C optimal
- pH: 4.5–7.0 (slightly acidic preferred, mimicking their natural blackwater habitats)
- Hardness: 1–8 dGH (very soft water)
- Requires clean, stable water with low nitrate levels (<20 mg/L).
Aquarium Setup:
- Substrate: Dark fine gravel or sand to enhance their vivid colours and replicate their natural riverbed environment.
- Decor: Dense vegetation (e.g., Java fern, Amazon sword, Cryptocoryne) and driftwood to mimic their blackwater habitat. Include floating plants (e.g., water sprite) to diffuse light. Provide open swimming areas.
- Filtration: Gentle filtration (e.g., sponge or low-flow canister filter) to maintain water quality without strong currents, as Cardinal Tetras prefer calm waters.
- Lighting: Subdued lighting to simulate their shaded natural habitat and reduce stress. Avoid intense lighting, which can fade their colours.
- Cover: A tight-fitting lid is recommended, as they may jump when startled.
Maintenance
- Water Changes: Perform 20–25% water changes weekly using dechlorinated water to maintain low nitrate levels and stable parameters. Avoid sudden changes in pH or temperature.
- Tank Cleaning: Lightly vacuum substrate to remove debris, preserving some organic matter to mimic their natural environment. Clean glass and decorations sparingly to avoid disrupting the tank’s ecosystem.
- Equipment Checks: Regularly inspect filters, heaters, and thermometers to ensure stability. Test water parameters weekly for pH, ammonia, nitrites, nitrates, and hardness.
- Monitoring: Observe for signs of stress (e.g., faded colours, clamped fins, or lethargy) or diseases like neon tetra disease (caused by Pleistophora parasites). Quarantine new fish to prevent disease introduction.
Diet
- Primary Food: Omnivorous with a preference for small foods due to their small mouths.
- Recommended Foods:
- High-quality micro-pellets or fine flake foods formulated for small tetras.
- Live or frozen foods such as brine shrimp, daphnia, cyclops, or bloodworms to enhance health and colouration.
- Occasional vegetable-based foods like spirulina flakes for dietary variety.
- Feeding Frequency: Feed small amounts 1–2 times daily, ensuring food is consumed within 2–3 minutes to prevent overfeeding and water pollution. They feed primarily in the mid-to-upper water column.
Behaviour and Compatibility
Behaviour:
Cardinal Tetras are peaceful, active, and schooling fish that thrive in groups of 6–12 or more. Larger schools reduce stress and enhance their shoaling Behaviour, creating a stunning visual display. They are shy and may hide if not kept in sufficient numbers or in overly bright tanks.
Compatibility:
- Compatible Tankmates: Small, peaceful fish like Neon Tetras, Ember Tetras, rasboras, corydoras, Otocinclus, and dwarf cichlids (e.g., Apistogramma). Non-aggressive bottom-dwellers like kuhli loaches are also suitable.
- Incompatible Tankmates: Avoid large, aggressive, or predatory fish (e.g., large cichlids, angelfish) and fin-nippers (e.g., tiger barbs), as Cardinal Tetras are small and vulnerable. Long-finned fish like bettas may also be stressed by their active swimming.
- Note: Their small size and peaceful nature make them ideal for calm community tanks with similar-sized species.
Breeding Behaviour
Breeding in Captivity: Challenging and rare in home aquariums due to their specific requirements and sensitivity. Commercial breeding often uses hormonal induction.
Picture for illustrative purposes only. Either come in store to view available stock or request pictures to be sent to you.
Please Note: Due to variations within species resulting from age, region, sex, etc., the actual livestock may not look identical to the image. Approximate size range may also vary between individual specimens.
