Cardinal Tetra

Cardinal Tetra

Scientific Name: Paracheirodon axelrodi
Common Names: Cardinal Tetra
Origin: South America (Brazil, Colombia, Venezuela – Rio Negro and Orinoco basins)
Adult Size: 2 inches (5 cm)
Lifespan: 3–5 years
Temperament: Peaceful, schooling
Swimming Zone: Midwater

Sales Description

The Cardinal Tetra is one of the most iconic and beloved freshwater fish in the aquarium hobby, admired for its striking electric blue stripe and vivid crimson red body that runs the full length of the fish. Unlike its close relative, the neon tetra, the cardinal’s red coloration extends from head to tail, offering a more intense and eye-catching display.

Cardinals are peaceful, social fish that thrive in schools of six or more, making them ideal for community aquariums and planted tanks. Their vibrant coloration stands out beautifully against driftwood, live plants, and darker substrates, especially under soft, subdued lighting.

Healthy, fully acclimated stock ensures vivid coloration and active schooling behavior right from the start.

Care Guide

Tank Requirements

Minimum Tank Size: 15–20 gallons (more for larger schools)

Biotope: Heavily planted, shaded areas, dark substrate recommended

Lighting: Low to moderate; floating plants help simulate natural habitat

Filtration: Gentle to moderate flow; avoid strong currents

Cover: Floating plants or leaf litter provide shelter and security

Water Parameters

Temperature: 74–82°F (23–28°C)

pH Range: 4.5–7.0 (prefer soft, slightly acidic water)

Hardness: Very soft to moderately hard

Water Changes: 20–30% weekly to maintain pristine water quality

Feeding & Diet

Diet: Omnivore

Feeding Frequency: 1–2 times daily

Preferred Foods: Micro pellets, flake food

Frozen or live foods: daphnia, baby brine shrimp, bloodworms

Occasional treats: Repashy Community Plus, Super Green

Notes: Feed a varied diet to ensure peak coloration and health

Behavior & Tankmates

Temperament: Very peaceful, ideal for community tanks

Schooling: Best kept in groups of at least 6–10; more is better

Compatible Tankmates: Small peaceful species like rasboras, otocinclus, pygmy corydoras, dwarf cichlids (Apistogramma, Nannacara), peaceful gouramis, endlers, and pencilfish

Avoid: Larger predatory fish or fin-nipping/aggressive species

Breeding Notes

Spawning Difficulty: Moderate to difficult

Setup: Separate soft-water breeding tank with dim lighting and fine-leaved plants or spawning mops

Behavior: Egg scatterers with no parental care

Fry Care: Eggs are light-sensitive; feed infusoria or green water, then baby brine shrimp