Origins and Classification
- Scientific Name: Paracheirodon axelrodi
- Family: Characidae (Tetras)
- Origin: Native to the upper Orinoco and Negro River basins in Brazil, Colombia, and Venezuela.
- Popularity: Renowned for its brilliant blue and red coloration and peaceful temperament, the Cardinal Tetra is one of the most admired community fish worldwide — often confused with the Neon Tetra, but larger and more vividly colored.
🎨 Appearance
- Color: Iridescent electric-blue stripe running from the eye to the tail, and a bright crimson-red stripe extending along the entire lower half of the body.
- Structure:
- Slender, streamlined body with transparent fins.
- Colors intensify in dim lighting or dark substrates.
- Size: Up to 2 inches (5 cm) — slightly larger than the Neon Tetra.
- Lifespan: 4–5 years, sometimes longer in well-maintained tanks.
🏡 Tank Requirements
- Tank Size: Minimum 15–20 gallons (best kept in groups of 8–12+).
- Water Parameters:
- Temperature: 74–82°F (23–28°C)
- pH: 5.0–7.0 (soft, slightly acidic water ideal)
- Hardness: 1–10 dGH
- Lighting: Dim or moderate; replicate their natural blackwater habitat.
- Substrate: Dark sand or fine gravel.
- Habitat Setup:
- Add driftwood, live plants, and leaf litter for shelter and comfort.
- Keep gentle filtration and low current flow.
- Use tannin-rich water (e.g., Indian almond leaves) to mimic Amazon conditions.
