Cardinal Tetra

The Cardinal Tetra (Paracheirodon axelrodi) is one of the most popular freshwater fish in the world, native to the blackwater rivers of South America. It is slightly larger and more colorful than the common Neon Tetra, featuring a brilliant neon-blue stripe and a vivid red stripe that runs the full length of its body. Growing to about 5 cm (2 inches), they are peaceful schooling fish that thrive in warm, soft, and acidic water. They are the crown jewel of many planted aquariums, looking spectacular in large shoals. Now In stock

Category: Fishes

Description

1. Origin & Habitat

Scientific Name: Paracheirodon axelrodi.
Origin: Native to the upper Orinoco and Negro River basins in South America (Brazil, Colombia, Venezuela).
Environment: In the wild, they inhabit slow-moving “blackwater” streams—water stained dark brown by decaying leaves and roots. This environment is typically very soft, acidic, and dimly lit.

2. Appearance (Cardinal vs. Neon)

The Key Difference: The easiest way to tell them apart from Neon Tetras is the red stripe.
- Neon Tetra: Red stripe starts at the middle of the body and goes to the tail.
- Cardinal Tetra: Red stripe runs the entire length of the bottom half of the body.
Iridescence: The upper stripe is an electric neon blue/green that reflects light. In a dark tank, they appear to “glow.”
Size: They grow slightly larger than Neons, reaching up to 5 cm (2 inches).

3. Water Requirements (Warmth Lover)

Temperature: Unlike the White Cloud Minnows you showed earlier, Cardinals are true tropical fish and love heat. They prefer 23°C – 29°C (73°F – 84°F).
Sensitivity: They are generally more sensitive to water quality changes than Black Neons. They should be added to mature, established tanks rather than brand new ones.
pH: They prefer soft, acidic water (pH 4.5 – 7.0).

4. Behavior & Tank Setup

Schooling: They are schooling fish and feel stressed if kept alone. You need a group of at least 6, though 15–20 creates a breathtaking display.
Temperament: Completely peaceful. They are excellent community fish but should not be kept with large fish (like Angelfish) that might mistake them for a snack.
Decor: They look best in tanks with dark substrate, driftwood, and plenty of plants. The dark background makes their colors appear much more intense.

5. Diet

Feeding: They are omnivores.
Recommendations: They will readily eat high-quality flakes and micro-pellets. For the best health and color, feed them live or frozen foods like daphnia and baby brine shrimp occasionally.