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Discovering the Dazzling Cardinal Tetra: A Gem of the Tetra Family

Updated: Aug 16, 2023

Dazzling Beauty: Introducing the Cardinal Tetra

If you're looking to add a touch of brilliance to your freshwater aquarium, look no further than Paraacheirodon axelrodi, the Cardinal Tetra a true gem of the Tetra Family. With its vibrant colors and captivating appearance, this relatively small but striking fish grows to a maximum length of around 2 inches (3cm). Often mistaken for its smaller, similarly colored cousin, the Neon Tetra (Paracheirodon innesi), the Cardinal Tetra boasts a unique and mesmerizing beauty.

Blackwater Cardinal Tetra Tank at The New England Aquarium aquascaped by Captain Duckweed

A Striking Coloration: The Cardinal Tetra's Distinctive Feature

One of the most distinguishing features of the Cardinal Tetra is its striking bright blue iridescent stripe that runs from the nares (nose) to the peduncle (where the caudal or tail fin attaches to the body). This stripe laterally bisects the silver dorsal portion from the robust red ventral section, which spans the entire length of the fish. This captivating coloration makes the Cardinal Tetra a standout addition to any aquatic community.


In the Wild: Discovering the Natural Habitat of the Cardinal Tetra

In their natural habitat, you can find Paraacheirodon axelrodi gracefully navigating the tannic, slow-moving waters and sandy streams of the Rio Negro and Orinoco tributaries. To ensure these beautiful fish thrive in your aquarium, it is crucial to maintain stable water parameters. Cardinal Tetras prefer acidic water but can tolerate a pH range of 3.5 to 7.5, KH between 1 to 6, and temperatures ranging from 72 to 88°F (23 to 31 °C). While they do not necessarily require black water to flourish, introducing tannins will enhance their radiancy, shimmering colors, and promote natural behaviors.

Creating the Perfect Environment: Providing for Cardinal Tetras' Needs

Creating an ideal environment for Cardinal Tetras involves providing them with dense vegetation, branches, and leaves. These elements not only add natural beauty to the aquarium but also offer ample hiding places for the fish to feel safe and secure. It is essential to strike a balance between hiding spots and open schooling areas to allow these social creatures to swim freely and display their captivating behavior.


A Kaleidoscope of Colors: The Impact of Grouping Cardinal Tetras

For an impressive display of color and interaction, it is recommended to keep Cardinal Tetras in groups of 10 or more. In larger numbers, they feel more confident, bringing out their full potential and revealing their true colors. Although Cardinal Tetras may appear timid at first, providing them with suitable tank-mates of similar size and temperament will further enhance their social behavior.

Repashy Igapo Explorer

A Balanced Diet: Feeding Cardinal Tetras for Optimal Health

Feeding Cardinal Tetras is a joy, as they are omnivorous and readily accept a variety of foods. Fish, shrimp, or algae flakes, as well as small pellet foods, make up the main part of their diet. To enrich their nutritional intake and add variety, consider supplementing their meals with frozen or live Daphnia, Baby Mysis, Brine Shrimp, Moina, or prepared gel foods like REPASHY. Using a vitamin supplement such as Vita-Chem and alternating foods will support their overall health and immune system.


Breeding: Growing a Colony

Breeding Cardinal Tetras can be a rewarding challenge, and success is often achieved in a species-only tank. Careful attention to water parameters, appropriate diet, and patience are key factors in encouraging these fish to breed. When conditions are favorable, a female Cardinal Tetra can lay hundreds of eggs in a single evening. Within approximately 24 hours, delicate wriggling fry with yolk sacs attached will appear, marking the beginning of a fascinating journey for dedicated aquarists.


In conclusion, the Cardinal Tetra (Paraacheirodon axelrodi) stands as a radiant gem among tetra species, captivating aquarium enthusiasts with its vibrant colors and distinctive bright blue iridescent stripe. With careful attention to their natural habitat, water parameters, and suitable environment, these captivating fish thrive in our aquariums. Offering dense vegetation, hiding spots, and grouping them in schools bring out their mesmerizing behavior and social nature. As we delight in feeding them a varied diet and explore the fascinating journey of breeding, we are reminded of our responsibility to preserve their beauty and wonder. The Cardinal Tetra's allure continues to grace our aquatic world, inspiring admiration and fostering a deep connection with these fascinating creatures.

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