Cardinal Tetra, lat. Paracheirodon axelrodi- Paracheirodon axelrodi distribution
Family: Characidae;
Genus: Paracheirodon;
Species and synonyms: Cardinal Tetra (Paracheirodon axelrodi, Cardinal Tetra, Red Neon Tetra, Cheirodon axelrodi).
GBIF:
Cardinal Tetra (lat. Paracheirodon axelrodi) is a species of ray-finned fish from the order Characiformes, family Characidae, genus Paracheirodon. One of the brightest and most popular aquarium fish, known for its intense red and blue coloration.
Distribution. The natural range of the Cardinal Tetra covers rivers and streams of South America, mainly in the Orinoco, Negro and Amazon river basins in Brazil, Colombia and Venezuela. The fish prefer slow-moving waters with sandy or muddy bottoms, often found in small rivers, streams and floodplain lakes with dense vegetation.
Care requirements. The Cardinal Tetra is a schooling fish that grows up to 4–5 cm in the aquarium. To keep a school (minimum 6–10 specimens), an aquarium of at least 60 liters with a length of 60 cm is recommended. It is important to keep them in schools, as they are social fish and feel comfortable only in a group. Optimal water parameters: temperature 24–28°C, hardness 5–15 dGH, pH 5.0–7.0. Filtration with moderate flow, aeration and weekly water changes of 20–25% are necessary. Dark sandy or fine gravel substrate, driftwood, stones and shelters are placed at the bottom. Plants are planted in the substrate, creating dense thickets, and open swimming areas are left.
Cardinal Tetras are omnivorous, feeding on small invertebrates, worms and zooplankton in the wild. In the aquarium, their diet should consist of high-quality fine flakes, pellets, live and frozen foods (brine shrimp, daphnia, cyclops, bloodworms). It is important to vary the diet and provide protein-rich food. Feed should be 2–3 times a day in small portions.
In the aquarium, Cardinal Tetras are active in the middle and upper water layers. They are peaceful and get along well with any peaceful fish. Recommended tankmates include other tetras, rasboras, danios, dwarf barbs, gouramis, corydoras and any small peaceful fish. It is not recommended to keep them with large or aggressive fish that may bully them or mistake them for food.
Breeding in home aquariums is possible under proper conditions. Cardinal Tetras are egg-laying fish, spawning on fine-leaved plants or special spawning substrates. They reach sexual maturity at 8–10 months. To stimulate spawning, water changes with fresh, soft and slightly acidic water, with a temperature increase to 26–28°C, are recommended. Spawning occurs in the morning hours. Eggs incubate for 1–2 days, fry begin to swim after 3–4 days. Fry are fed infusoria, Artemia nauplii and fine dry food.
The Cardinal Tetra gets its name from its bright coloration: the upper half of the body shines with a bright blue neon color, the lower half is intensely red. Unlike the common neon tetra, the cardinal tetra's red color extends along the entire body. Males are slimmer and brighter than females. Life expectancy is 3–5 years.