Cardinal Tetra

The Cardinal Tetra (Paracheirodon axelrodi) is a small, freshwater fish native to the Amazon Basin, particularly found in the blackwaters of Colombia and Brazil. Distinguished by its vivid blue body and a striking red stripe that runs from the middle of the body to the base of the tail, this species showcases a remarkable iridescence that makes it a favorite among aquarists. Typically growing to about 5 centimeters in length, the Cardinal Tetra is a schooling fish, preferring to be kept in groups of six or more to exhibit its natural behavior and coloration fully.

In the wild, Cardinal Tetras inhabit slow-moving streams and rivers, often thriving in areas with dense vegetation that provides both cover and breeding grounds. Their natural habitat features soft, acidic waters with a pH ranging from 5.5 to 7.0, and temperatures typically between 24°C and 28°C. The species is known for its peaceful disposition, making it an excellent choice for community tanks with other non-aggressive fish.

Behaviorally, Cardinal Tetras are social and active swimmers. They spend much of their time in the mid to upper levels of the water column, darting in and out of plants. Their vibrant colors are not only stunning but also serve as a means of communication within their school. During breeding, males can be seen displaying their colors more vividly, particularly when courting females.

The Cardinal Tetra is also known for its sensitivity to water quality, which makes it an excellent indicator species for aquarium health. Proper care and maintenance of their environment are crucial to ensure their vibrant colors and lively behavior are maintained in captivity.

When caring for Cardinal Tetras, maintaining stable water parameters is essential. They thrive in soft, slightly acidic water with a pH between 6.0 and 7.0 and a temperature range of 24°C to 28°C. Regular water changes are recommended to keep their environment clean and to prevent the buildup of harmful substances. A minimum tank size of 40 liters is advisable to accommodate a small school of these fish, as they feel safer and display more natural behaviors in larger groups.

Feeding Cardinal Tetras is straightforward, as they are omnivorous. A varied diet consisting of high-quality flake foods, micro-pellets, and occasional live or frozen foods, such as brine shrimp or daphnia, will keep them healthy and vibrant. It’s important to avoid overfeeding, as this can lead to water quality issues.

In terms of compatibility, Cardinal Tetras are peaceful and can be kept with a variety of species, including other tetras, rasboras, and small peaceful cichlids. When introducing them to a new tank, gradual acclimation over several hours is recommended to minimize stress. Quarantine new arrivals for at least two weeks before adding them to a community tank to ensure they are free from diseases.

Cardinal Tetras are suitable for shipping due to their hardiness, but it is crucial to maintain optimal conditions during transport. Packing density should not exceed 1 liter of water per fish to prevent stress and injury. Ideal shipping temperatures range between 22°C and 26°C. These fish are not listed under CITES, which simplifies export regulations.