Cardinal Tetra

The Cardinal Tetra (Paracheirodon axelrodi) is a popular freshwater tropical fish recognized for its stunning appearance. Its vibrant iridescent blue stripe and fiery red lower body run the entire length of its small frame, measuring just 3 to 5 cm.

Natural Habitat and Origins

• Native Range: Found in South America, specifically within the upper Rio Negro and Orinoco River basins.
• Environment: Prefers slow-moving, shallow blackwater streams or shaded forest creeks filled with dense leaf litter and submerged wood.
• Ecosystem Role:
  • Lives in large schools near vegetation for protection against predators.
  • Feeds on microcrustaceans, small insect larvae, and detritus.
  • Buying wild-caught specimens supports sustainable local indigenous fishing communities in the Amazon basin, as many wild fish perish during the dry season due to declining water levels.

Aquarium Care and Requirements

• Tank Size: Minimum of 10 gallons (approx. 38–60 liters) to support a proper school.
• Schooling: Must be kept in groups of at least 6 to 10 individuals to reduce stress and encourage natural behavior.
• Water Parameters:
  • Temperature: 23°C to 27°C (73°F–81°F).
  • pH: Slightly acidic, ranging from 4.5 to 7.0.
  • Water Hardness: Soft water, 1–8 dGH.
• Lifespan: 2 to 5 years in proper captive conditions, compared to roughly 1 year in harsh seasonal wild cycles.

This species thrives when its natural habitat and social behaviors are replicated, making it a rewarding addition to any freshwater aquarium.