Cardinal Tetra (Paracheirodon axelrodi)
The Cardinal Tetra is seemingly one of the most popular fish species for the aquarium. It is often confused with the Neon tetra as it is somewhat similar in appearance.
Cardinal Tetras are suitable for beginner aquarists as they are relatively hardy, easy to care for and very colourful. Like most Tetras, these are peaceful and make an excellent addition to any community aquarium, but you can also keep them in a species only tank too.
The Cardinal Tetra is a very friendly fish, and you should keep them in larger groups so they can create tight groups and create a dazzling shoaling effect that forms the focal point of any aquarium. These fish are also much more confident when around others of their kind. If kept alone, they can become shy and stressed, and even lose some colour. Aggressive fish easily bully them as they are unable to defend themselves.
They are more susceptible to poor water quality than their Neon cousins and prefer heavily planted aquariums that replicate a more natural habitat.
Cardinal Tetras bodies are typically slender and torpedo-shaped with blue and red colouring. A red bar runs along the lower side from head to tail, and a blue stripe sits just on top. You can also find them in golds and silvers; however, these are far less common.
| Quick Facts | |
|---|---|
| Scientific Name | Paracheirodon axelrodi |
| Other Names | Red Neon, Roter Neon |
| Classification | Actinopterygii |
| Order | Characiformes |
| Family | Characidae |
| Genus | Paracheirodon |
| Origins | South America |
| Temperament | Peaceful |
| Aquarium Level | Middle - Top |
| Difficulty | Intermediate |
| Shoaling | Yes |
| Best kept as | Groups 6+ |
| Diet | Omnivore |
| Reproduction | Egg-Scatterer |
| Lifespan | 4 - 5 years |
| Water Parameters | |
|---|---|
| Water Type | Freshwater |
| PH | 3.5 - 7.5 |
| GH | 1 - 5 |
| KH | 2 - 6 |
| TDS | 20 - 215 |
| Temperature | |
| 73 - 84℉ 23 - 29℃ | |
Natural Habitat
This species is endemic to the upper Orinoco and the Rio Negro river basins located in Columbia, Venezuela and Brazil in South America. They inhabit slow-moving and heavily vegetated creeks, rivers, canals and streams. These fish also prefer shaded areas that have low or subdued lighting.
Other Tetras of interest
What to feed the Cardinal Tetra
Cardinal Tetras will accept virtually any form of aquarium food. However, you should provide them with a balanced diet of high-quality flakes, pellets and granules, frozen and live fares such as Brine shrimp, daphnia, Tubifex and bloodworm. You should also include green vegetables in their diet as this will help promote the best health and colour for your fish.
How to Sex the Cardinal Tetra
Male and female Cardinal Tetras are similar in appearance and colour, making it quite challenging to determine gender when young. However, as the fish mature, this becomes easier to define as females become plumper and more extensive than their male counterparts, whereas males have a hooked anal fin and are much slimmer and leaner.
How to Breed the Cardinal Tetra
When it comes to breeding the Cardinal Tetra, it is advisable to provide them with a separate dimly lit breeding tank comprising very soft water and plenty of plants and moss. It would also help if you conditioned the fish with live and frozen foods, encouraging spawning behaviour.
When the bonded pair is ready to spawn, the female's stomach will become plump from eggs. It is at this point you should place them in the breeding tank. The female will allow a male to swim beside her as they move around plants. The fish will then release eggs and sperm.
If breeding has been successful, the pair will typically breed during the evening, where the female will lay anything up to 500 eggs. Once the eggs have been applied, you should remove the parents as quickly as possible otherwise, they may consume them. The eggs will usually hatch around three days later.
Initially, the fry will be too small to eat the same as the adults, so it is best to feed them small foods like infusoria until they are big enough to accept more significant foods. The young will be photosensitive once hatched, so gradually raise the light intensity back to normal conditions.
Around 8 to 12 weeks later, the fry should have the colours to match the adults.