Mixed Variety
A mixed variety cardinal tetra is usually an assorted or unselected group of Paracheirodon axelrodi rather than a recognized strain. Cardinal tetras are small South American characins from blackwater and clearwater systems of the Rio Negro and upper Orinoco region. The wild-type pattern is the one most aquarists know: an electric blue stripe above a red band that runs nearly the full length of the body, a useful difference from the neon tetra's shorter red stripe. Commercial lots may contain fish from different collection areas or captive-bred sources.
In aquariums, mixed-variety fish should be managed for health and compatibility rather than line breeding. They do best in groups, with warm stable water, subdued lighting, cover from plants or leaf litter, and small foods suited to their mouths. Quarantine is important because tetras are often shipped in large numbers and stress can expose parasites or bacterial problems. Breeding is possible but not casual; pairs scatter tiny eggs that need soft acidic water and low light, so most keepers maintain them as display shoals.
Colors: Wild Type