A stunning schooling fish native to the upper Orinoco and Rio Negro basins in South America. Famous for its brilliant iridescent blue line and a vivid red stripe that extends the full length of its body (distinguishing it from the Neon Tetra). They are strictly schooling fish that thrive in warm, acidic blackwater environments.
At a Glance
Tank Requirements
Water Parameters
Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard wild-type Cardinal Tetra. Needs to be kept in a group of at least 6 (preferably 10+) to feel secure and exhibit natural schooling behavior. Dim lighting or tannin-stained water brings out their best colors.
Differs in 1 trait from base species
Also known as: Wild Type
Albino / Gold
A selectively bred morph that lacks dark pigmentation. The body appears pinkish-gold, but they retain the distinctive iridescent blue and red stripes. Husbandry is identical to the standard form.
Differs in 1 trait from base species
Also known as: Gold Cardinal, Albino Cardinal
Cardinal Tetra Care Summary
The Cardinal Tetra, scientifically known as Paracheirodon axelrodi, belongs to the Characins family group. Adults reach a maximum size of approximately 4 cm and have a fusiform body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the mid-level zone of the aquarium and produces a low level of biological waste.
To thrive, the Cardinal Tetra requires a freshwater only aquarium with a minimum volume of 55 litres and a tank length of at least 60 cm. Water temperature should be maintained between 24°C and 29°C, with a pH range of 4–7 and a general hardness of 1–8 dGH. A low water flow is preferred. To replicate their natural habitat, the tank should include leaf litter/blackwater, driftwood (digestion/hiding), and plants - densely covered.
As a schooling species, Cardinal Tetra should be kept in groups of at least 6. This species is available in 2 varieties: Standard and Albino / Gold. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Similar Species
Neon Tetra
Paracheirodon innesi
One of the most iconic freshwater fish in the hobby, famous for its striking iridescent blue and red stripes. Originally from the blackwater streams of the Amazon basin, they prefer slightly cooler water than many tropical fish and must be kept in schools to thrive, display natural behaviors, and feel secure.
Ember Tetra
Hyphessobrycon amandae
The Ember Tetra is a striking, fiery orange-red nano fish native to the Araguaia River basin in Brazil. Extremely peaceful and active, they are perfect for planted and blackwater aquariums. They are tight schoolers and must be kept in groups to feel secure and display their best colors.
Rummy-Nose Tetra
Hemigrammus rhodostomus
Renowned as the tightest schooling fish in the freshwater hobby. They feature a bright red nose, a silver body, and a black-and-white checkered tail. They are excellent 'indicator fish'; their red noses will fade to pale pink if water quality drops or the fish are stressed. While there are three very similar species (H. rhodostomus, H. bleheri, P. georgiae) often sold under the same name, their care requirements are identical.
Red Rainbowfish
Glossolepis incisus
Native to Lake Sentani in Indonesia, this species is famous for the brilliant salmon-red coloration of mature males. They are large, active schooling fish that develop a distinct high-arched back as they age. Females are vastly different in appearance (olive-gold). They require hard, alkaline water and plenty of swimming space.
Panda Corydoras
Corydoras panda
A highly popular, peaceful schooling catfish easily identified by its black eye patches and spotted dorsal/tail fins, resembling a giant panda. Native to the cooler waters of the Ucayali river system in Peru, they require slightly lower temperatures than many standard tropical community fish. They are strict bottom-dwellers that sift through the substrate for food.
Neon Blue Goby
Stiphodon atropurpureus
A stunning, specialized freshwater goby native to fast-flowing hill streams in Asia. Males display brilliant neon blue metallic coloration, while females are striped. They are specialized biofilm grazers ('Aufwuchs' eaters) and require mature tanks with established algae/biofilm stones. They are obligate stream dwellers requiring high oxygen and strong flow.